Imported from pngcrush-1.7.11.tarv1.7.11

32 files changed, 2233 insertions, 304 deletions

diff --git a/ChangeLog.html b/ChangeLog.html
index f5815ccbb..f56305120 100644
--- a/ChangeLog.html
+++ b/ChangeLog.html
@@ -3,6 +3,8 @@
 
 Change log:
 
+Version 1.7.11  (built with libpng-1.4.2 and zlib-1.2.5)
+
 Version 1.7.10  (built with libpng-1.4.1 and zlib-1.2.3.9)
   Added missing "(...)" in png_get_uint_32().
   Only compile png_get_uint_32(), etc., when PNG_LIBPNG_VER < 1.2.9
diff --git a/crc32.c b/crc32.c
index 1acc7ed8e..91be372d2 100644
--- a/crc32.c
+++ b/crc32.c
@@ -1,5 +1,5 @@
 /* crc32.c -- compute the CRC-32 of a data stream
- * Copyright (C) 1995-2006 Mark Adler
+ * Copyright (C) 1995-2006, 2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  *
  * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster
@@ -221,7 +221,7 @@ const unsigned long FAR * ZEXPORT get_crc_table()
 unsigned long ZEXPORT crc32(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    unsigned len;
+    uInt len;
 {
     if (buf == Z_NULL) return 0UL;
 
diff --git a/deflate.c b/deflate.c
index fcd698cc6..5c4022f3d 100644
--- a/deflate.c
+++ b/deflate.c
@@ -52,7 +52,7 @@
 #include "deflate.h"
 
 const char deflate_copyright[] =
-   " deflate 1.2.4 Copyright 1995-2010 Jean-loup Gailly and Mark Adler ";
+   " deflate 1.2.5 Copyright 1995-2010 Jean-loup Gailly and Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
diff --git a/deflate.h b/deflate.h
index f53deba85..cbf0d1ea5 100644
--- a/deflate.h
+++ b/deflate.h
@@ -1,5 +1,5 @@
 /* deflate.h -- internal compression state
- * Copyright (C) 1995-2009 Jean-loup Gailly
+ * Copyright (C) 1995-2010 Jean-loup Gailly
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -290,13 +290,13 @@ typedef struct internal_state {
    memory checker errors from longest match routines */
 
         /* in trees.c */
-void _tr_init         OF((deflate_state *s));
-int  _tr_tally        OF((deflate_state *s, unsigned dist, unsigned lc));
-void _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
-                          int last));
-void _tr_align        OF((deflate_state *s));
-void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
-                          int last));
+void ZLIB_INTERNAL _tr_init OF((deflate_state *s));
+int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
+void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+void ZLIB_INTERNAL _tr_align OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
 
 #define d_code(dist) \
    ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
@@ -309,11 +309,11 @@ void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
 /* Inline versions of _tr_tally for speed: */
 
 #if defined(GEN_TREES_H) || !defined(STDC)
-  extern uch _length_code[];
-  extern uch _dist_code[];
+  extern uch ZLIB_INTERNAL _length_code[];
+  extern uch ZLIB_INTERNAL _dist_code[];
 #else
-  extern const uch _length_code[];
-  extern const uch _dist_code[];
+  extern const uch ZLIB_INTERNAL _length_code[];
+  extern const uch ZLIB_INTERNAL _dist_code[];
 #endif
 
 # define _tr_tally_lit(s, c, flush) \
diff --git a/gzclose.c b/gzclose.c
new file mode 100644
index 000000000..caeb99a31
--- /dev/null
+++ b/gzclose.c
@@ -0,0 +1,25 @@
+/* gzclose.c -- zlib gzclose() function
+ * Copyright (C) 2004, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* gzclose() is in a separate file so that it is linked in only if it is used.
+   That way the other gzclose functions can be used instead to avoid linking in
+   unneeded compression or decompression routines. */
+int ZEXPORT gzclose(file)
+    gzFile file;
+{
+#ifndef NO_GZCOMPRESS
+    gz_statep state;
+
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    return state->mode == GZ_READ ? gzclose_r(file) : gzclose_w(file);
+#else
+    return gzclose_r(file);
+#endif
+}
diff --git a/gzguts.h b/gzguts.h
new file mode 100644
index 000000000..0f8fb79f8
--- /dev/null
+++ b/gzguts.h
@@ -0,0 +1,132 @@
+/* gzguts.h -- zlib internal header definitions for gz* operations
+ * Copyright (C) 2004, 2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifdef _LARGEFILE64_SOURCE
+#  ifndef _LARGEFILE_SOURCE
+#    define _LARGEFILE_SOURCE 1
+#  endif
+#  ifdef _FILE_OFFSET_BITS
+#    undef _FILE_OFFSET_BITS
+#  endif
+#endif
+
+#if ((__GNUC__-0) * 10 + __GNUC_MINOR__-0 >= 33) && !defined(NO_VIZ)
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include <stdio.h>
+#include "zlib.h"
+#ifdef STDC
+#  include <string.h>
+#  include <stdlib.h>
+#  include <limits.h>
+#endif
+#include <fcntl.h>
+
+#ifdef NO_DEFLATE       /* for compatibility with old definition */
+#  define NO_GZCOMPRESS
+#endif
+
+#ifdef _MSC_VER
+#  include <io.h>
+#  define vsnprintf _vsnprintf
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+/* gz* functions always use library allocation functions */
+#ifndef STDC
+  extern voidp  malloc OF((uInt size));
+  extern void   free   OF((voidpf ptr));
+#endif
+
+/* get errno and strerror definition */
+#if defined UNDER_CE
+#  include <windows.h>
+#  define zstrerror() gz_strwinerror((DWORD)GetLastError())
+#else
+#  ifdef STDC
+#    include <errno.h>
+#    define zstrerror() strerror(errno)
+#  else
+#    define zstrerror() "stdio error (consult errno)"
+#  endif
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
+    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+    ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+    ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+    ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+#endif
+
+/* default i/o buffer size -- double this for output when reading */
+#define GZBUFSIZE 8192
+
+/* gzip modes, also provide a little integrity check on the passed structure */
+#define GZ_NONE 0
+#define GZ_READ 7247
+#define GZ_WRITE 31153
+#define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
+
+/* values for gz_state how */
+#define LOOK 0      /* look for a gzip header */
+#define COPY 1      /* copy input directly */
+#define GZIP 2      /* decompress a gzip stream */
+
+/* internal gzip file state data structure */
+typedef struct {
+        /* used for both reading and writing */
+    int mode;               /* see gzip modes above */
+    int fd;                 /* file descriptor */
+    char *path;             /* path or fd for error messages */
+    z_off64_t pos;          /* current position in uncompressed data */
+    unsigned size;          /* buffer size, zero if not allocated yet */
+    unsigned want;          /* requested buffer size, default is GZBUFSIZE */
+    unsigned char *in;      /* input buffer */
+    unsigned char *out;     /* output buffer (double-sized when reading) */
+    unsigned char *next;    /* next output data to deliver or write */
+        /* just for reading */
+    unsigned have;          /* amount of output data unused at next */
+    int eof;                /* true if end of input file reached */
+    z_off64_t start;        /* where the gzip data started, for rewinding */
+    z_off64_t raw;          /* where the raw data started, for seeking */
+    int how;                /* 0: get header, 1: copy, 2: decompress */
+    int direct;             /* true if last read direct, false if gzip */
+        /* just for writing */
+    int level;              /* compression level */
+    int strategy;           /* compression strategy */
+        /* seek request */
+    z_off64_t skip;         /* amount to skip (already rewound if backwards) */
+    int seek;               /* true if seek request pending */
+        /* error information */
+    int err;                /* error code */
+    char *msg;              /* error message */
+        /* zlib inflate or deflate stream */
+    z_stream strm;          /* stream structure in-place (not a pointer) */
+} gz_state;
+typedef gz_state FAR *gz_statep;
+
+/* shared functions */
+void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
+#if defined UNDER_CE
+char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
+#endif
+
+/* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
+   value -- needed when comparing unsigned to z_off64_t, which is signed
+   (possible z_off64_t types off_t, off64_t, and long are all signed) */
+#ifdef INT_MAX
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
+#else
+unsigned ZLIB_INTERNAL gz_intmax OF((void));
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
+#endif
diff --git a/gzlib.c b/gzlib.c
new file mode 100644
index 000000000..603e60ed5
--- /dev/null
+++ b/gzlib.c
@@ -0,0 +1,537 @@
+/* gzlib.c -- zlib functions common to reading and writing gzip files
+ * Copyright (C) 2004, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
+#  define LSEEK lseek64
+#else
+#  define LSEEK lseek
+#endif
+
+/* Local functions */
+local void gz_reset OF((gz_statep));
+local gzFile gz_open OF((const char *, int, const char *));
+
+#if defined UNDER_CE
+
+/* Map the Windows error number in ERROR to a locale-dependent error message
+   string and return a pointer to it.  Typically, the values for ERROR come
+   from GetLastError.
+
+   The string pointed to shall not be modified by the application, but may be
+   overwritten by a subsequent call to gz_strwinerror
+
+   The gz_strwinerror function does not change the current setting of
+   GetLastError. */
+char ZLIB_INTERNAL *gz_strwinerror (error)
+     DWORD error;
+{
+    static char buf[1024];
+
+    wchar_t *msgbuf;
+    DWORD lasterr = GetLastError();
+    DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
+        | FORMAT_MESSAGE_ALLOCATE_BUFFER,
+        NULL,
+        error,
+        0, /* Default language */
+        (LPVOID)&msgbuf,
+        0,
+        NULL);
+    if (chars != 0) {
+        /* If there is an \r\n appended, zap it.  */
+        if (chars >= 2
+            && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
+            chars -= 2;
+            msgbuf[chars] = 0;
+        }
+
+        if (chars > sizeof (buf) - 1) {
+            chars = sizeof (buf) - 1;
+            msgbuf[chars] = 0;
+        }
+
+        wcstombs(buf, msgbuf, chars + 1);
+        LocalFree(msgbuf);
+    }
+    else {
+        sprintf(buf, "unknown win32 error (%ld)", error);
+    }
+
+    SetLastError(lasterr);
+    return buf;
+}
+
+#endif /* UNDER_CE */
+
+/* Reset gzip file state */
+local void gz_reset(state)
+    gz_statep state;
+{
+    if (state->mode == GZ_READ) {   /* for reading ... */
+        state->have = 0;            /* no output data available */
+        state->eof = 0;             /* not at end of file */
+        state->how = LOOK;          /* look for gzip header */
+        state->direct = 1;          /* default for empty file */
+    }
+    state->seek = 0;                /* no seek request pending */
+    gz_error(state, Z_OK, NULL);    /* clear error */
+    state->pos = 0;                 /* no uncompressed data yet */
+    state->strm.avail_in = 0;       /* no input data yet */
+}
+
+/* Open a gzip file either by name or file descriptor. */
+local gzFile gz_open(path, fd, mode)
+    const char *path;
+    int fd;
+    const char *mode;
+{
+    gz_statep state;
+
+    /* allocate gzFile structure to return */
+    state = malloc(sizeof(gz_state));
+    if (state == NULL)
+        return NULL;
+    state->size = 0;            /* no buffers allocated yet */
+    state->want = GZBUFSIZE;    /* requested buffer size */
+    state->msg = NULL;          /* no error message yet */
+
+    /* interpret mode */
+    state->mode = GZ_NONE;
+    state->level = Z_DEFAULT_COMPRESSION;
+    state->strategy = Z_DEFAULT_STRATEGY;
+    while (*mode) {
+        if (*mode >= '0' && *mode <= '9')
+            state->level = *mode - '0';
+        else
+            switch (*mode) {
+            case 'r':
+                state->mode = GZ_READ;
+                break;
+#ifndef NO_GZCOMPRESS
+            case 'w':
+                state->mode = GZ_WRITE;
+                break;
+            case 'a':
+                state->mode = GZ_APPEND;
+                break;
+#endif
+            case '+':       /* can't read and write at the same time */
+                free(state);
+                return NULL;
+            case 'b':       /* ignore -- will request binary anyway */
+                break;
+            case 'f':
+                state->strategy = Z_FILTERED;
+                break;
+            case 'h':
+                state->strategy = Z_HUFFMAN_ONLY;
+                break;
+            case 'R':
+                state->strategy = Z_RLE;
+                break;
+            case 'F':
+                state->strategy = Z_FIXED;
+            default:        /* could consider as an error, but just ignore */
+                ;
+            }
+        mode++;
+    }
+
+    /* must provide an "r", "w", or "a" */
+    if (state->mode == GZ_NONE) {
+        free(state);
+        return NULL;
+    }
+
+    /* save the path name for error messages */
+    state->path = malloc(strlen(path) + 1);
+    if (state->path == NULL) {
+        free(state);
+        return NULL;
+    }
+    strcpy(state->path, path);
+
+    /* open the file with the appropriate mode (or just use fd) */
+    state->fd = fd != -1 ? fd :
+        open(path,
+#ifdef O_LARGEFILE
+            O_LARGEFILE |
+#endif
+#ifdef O_BINARY
+            O_BINARY |
+#endif
+            (state->mode == GZ_READ ?
+                O_RDONLY :
+                (O_WRONLY | O_CREAT | (
+                    state->mode == GZ_WRITE ?
+                        O_TRUNC :
+                        O_APPEND))),
+            0666);
+    if (state->fd == -1) {
+        free(state->path);
+        free(state);
+        return NULL;
+    }
+    if (state->mode == GZ_APPEND)
+        state->mode = GZ_WRITE;         /* simplify later checks */
+
+    /* save the current position for rewinding (only if reading) */
+    if (state->mode == GZ_READ) {
+        state->start = LSEEK(state->fd, 0, SEEK_CUR);
+        if (state->start == -1) state->start = 0;
+    }
+
+    /* initialize stream */
+    gz_reset(state);
+
+    /* return stream */
+    return (gzFile)state;
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen64(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzdopen(fd, mode)
+    int fd;
+    const char *mode;
+{
+    char *path;         /* identifier for error messages */
+    gzFile gz;
+
+    if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL)
+        return NULL;
+    sprintf(path, "<fd:%d>", fd);   /* for debugging */
+    gz = gz_open(path, fd, mode);
+    free(path);
+    return gz;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzbuffer(file, size)
+    gzFile file;
+    unsigned size;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* make sure we haven't already allocated memory */
+    if (state->size != 0)
+        return -1;
+
+    /* check and set requested size */
+    if (size == 0)
+        return -1;
+    state->want = size;
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzrewind(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* back up and start over */
+    if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
+        return -1;
+    gz_reset(state);
+    return 0;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzseek64(file, offset, whence)
+    gzFile file;
+    z_off64_t offset;
+    int whence;
+{
+    unsigned n;
+    z_off64_t ret;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* check that there's no error */
+    if (state->err != Z_OK)
+        return -1;
+
+    /* can only seek from start or relative to current position */
+    if (whence != SEEK_SET && whence != SEEK_CUR)
+        return -1;
+
+    /* normalize offset to a SEEK_CUR specification */
+    if (whence == SEEK_SET)
+        offset -= state->pos;
+    else if (state->seek)
+        offset += state->skip;
+    state->seek = 0;
+
+    /* if within raw area while reading, just go there */
+    if (state->mode == GZ_READ && state->how == COPY &&
+        state->pos + offset >= state->raw) {
+        ret = LSEEK(state->fd, offset - state->have, SEEK_CUR);
+        if (ret == -1)
+            return -1;
+        state->have = 0;
+        state->eof = 0;
+        state->seek = 0;
+        gz_error(state, Z_OK, NULL);
+        state->strm.avail_in = 0;
+        state->pos += offset;
+        return state->pos;
+    }
+
+    /* calculate skip amount, rewinding if needed for back seek when reading */
+    if (offset < 0) {
+        if (state->mode != GZ_READ)         /* writing -- can't go backwards */
+            return -1;
+        offset += state->pos;
+        if (offset < 0)                     /* before start of file! */
+            return -1;
+        if (gzrewind(file) == -1)           /* rewind, then skip to offset */
+            return -1;
+    }
+
+    /* if reading, skip what's in output buffer (one less gzgetc() check) */
+    if (state->mode == GZ_READ) {
+        n = GT_OFF(state->have) || (z_off64_t)state->have > offset ?
+            (unsigned)offset : state->have;
+        state->have -= n;
+        state->next += n;
+        state->pos += n;
+        offset -= n;
+    }
+
+    /* request skip (if not zero) */
+    if (offset) {
+        state->seek = 1;
+        state->skip = offset;
+    }
+    return state->pos + offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzseek(file, offset, whence)
+    gzFile file;
+    z_off_t offset;
+    int whence;
+{
+    z_off64_t ret;
+
+    ret = gzseek64(file, (z_off64_t)offset, whence);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gztell64(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* return position */
+    return state->pos + (state->seek ? state->skip : 0);
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gztell(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gztell64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzoffset64(file)
+    gzFile file;
+{
+    z_off64_t offset;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* compute and return effective offset in file */
+    offset = LSEEK(state->fd, 0, SEEK_CUR);
+    if (offset == -1)
+        return -1;
+    if (state->mode == GZ_READ)             /* reading */
+        offset -= state->strm.avail_in;     /* don't count buffered input */
+    return offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzoffset(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gzoffset64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzeof(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return 0;
+
+    /* return end-of-file state */
+    return state->mode == GZ_READ ?
+        (state->eof && state->strm.avail_in == 0 && state->have == 0) : 0;
+}
+
+/* -- see zlib.h -- */
+const char * ZEXPORT gzerror(file, errnum)
+    gzFile file;
+    int *errnum;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return NULL;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return NULL;
+
+    /* return error information */
+    if (errnum != NULL)
+        *errnum = state->err;
+    return state->msg == NULL ? "" : state->msg;
+}
+
+/* -- see zlib.h -- */
+void ZEXPORT gzclearerr(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return;
+
+    /* clear error and end-of-file */
+    if (state->mode == GZ_READ)
+        state->eof = 0;
+    gz_error(state, Z_OK, NULL);
+}
+
+/* Create an error message in allocated memory and set state->err and
+   state->msg accordingly.  Free any previous error message already there.  Do
+   not try to free or allocate space if the error is Z_MEM_ERROR (out of
+   memory).  Simply save the error message as a static string.  If there is an
+   allocation failure constructing the error message, then convert the error to
+   out of memory. */
+void ZLIB_INTERNAL gz_error(state, err, msg)
+    gz_statep state;
+    int err;
+    const char *msg;
+{
+    /* free previously allocated message and clear */
+    if (state->msg != NULL) {
+        if (state->err != Z_MEM_ERROR)
+            free(state->msg);
+        state->msg = NULL;
+    }
+
+    /* set error code, and if no message, then done */
+    state->err = err;
+    if (msg == NULL)
+        return;
+
+    /* for an out of memory error, save as static string */
+    if (err == Z_MEM_ERROR) {
+        state->msg = (char *)msg;
+        return;
+    }
+
+    /* construct error message with path */
+    if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
+        state->err = Z_MEM_ERROR;
+        state->msg = (char *)"out of memory";
+        return;
+    }
+    strcpy(state->msg, state->path);
+    strcat(state->msg, ": ");
+    strcat(state->msg, msg);
+    return;
+}
+
+#ifndef INT_MAX
+/* portably return maximum value for an int (when limits.h presumed not
+   available) -- we need to do this to cover cases where 2's complement not
+   used, since C standard permits 1's complement and sign-bit representations,
+   otherwise we could just use ((unsigned)-1) >> 1 */
+unsigned ZLIB_INTERNAL gz_intmax()
+{
+    unsigned p, q;
+
+    p = 1;
+    do {
+        q = p;
+        p <<= 1;
+        p++;
+    } while (p > q);
+    return q >> 1;
+}
+#endif
diff --git a/gzread.c b/gzread.c
new file mode 100644
index 000000000..548201ab0
--- /dev/null
+++ b/gzread.c
@@ -0,0 +1,653 @@
+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004, 2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
+local int gz_avail OF((gz_statep));
+local int gz_next4 OF((gz_statep, unsigned long *));
+local int gz_head OF((gz_statep));
+local int gz_decomp OF((gz_statep));
+local int gz_make OF((gz_statep));
+local int gz_skip OF((gz_statep, z_off64_t));
+
+/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from
+   state->fd, and update state->eof, state->err, and state->msg as appropriate.
+   This function needs to loop on read(), since read() is not guaranteed to
+   read the number of bytes requested, depending on the type of descriptor. */
+local int gz_load(state, buf, len, have)
+    gz_statep state;
+    unsigned char *buf;
+    unsigned len;
+    unsigned *have;
+{
+    int ret;
+
+    *have = 0;
+    do {
+        ret = read(state->fd, buf + *have, len - *have);
+        if (ret <= 0)
+            break;
+        *have += ret;
+    } while (*have < len);
+    if (ret < 0) {
+        gz_error(state, Z_ERRNO, zstrerror());
+        return -1;
+    }
+    if (ret == 0)
+        state->eof = 1;
+    return 0;
+}
+
+/* Load up input buffer and set eof flag if last data loaded -- return -1 on
+   error, 0 otherwise.  Note that the eof flag is set when the end of the input
+   file is reached, even though there may be unused data in the buffer.  Once
+   that data has been used, no more attempts will be made to read the file.
+   gz_avail() assumes that strm->avail_in == 0. */
+local int gz_avail(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    if (state->err != Z_OK)
+        return -1;
+    if (state->eof == 0) {
+        if (gz_load(state, state->in, state->size,
+                (unsigned *)&(strm->avail_in)) == -1)
+            return -1;
+        strm->next_in = state->in;
+    }
+    return 0;
+}
+
+/* Get next byte from input, or -1 if end or error. */
+#define NEXT() ((strm->avail_in == 0 && gz_avail(state) == -1) ? -1 : \
+                (strm->avail_in == 0 ? -1 : \
+                 (strm->avail_in--, *(strm->next_in)++)))
+
+/* Get a four-byte little-endian integer and return 0 on success and the value
+   in *ret.  Otherwise -1 is returned and *ret is not modified. */
+local int gz_next4(state, ret)
+    gz_statep state;
+    unsigned long *ret;
+{
+    int ch;
+    unsigned long val;
+    z_streamp strm = &(state->strm);
+
+    val = NEXT();
+    val += (unsigned)NEXT() << 8;
+    val += (unsigned long)NEXT() << 16;
+    ch = NEXT();
+    if (ch == -1)
+        return -1;
+    val += (unsigned long)ch << 24;
+    *ret = val;
+    return 0;
+}
+
+/* Look for gzip header, set up for inflate or copy.  state->have must be zero.
+   If this is the first time in, allocate required memory.  state->how will be
+   left unchanged if there is no more input data available, will be set to COPY
+   if there is no gzip header and direct copying will be performed, or it will
+   be set to GZIP for decompression, and the gzip header will be skipped so
+   that the next available input data is the raw deflate stream.  If direct
+   copying, then leftover input data from the input buffer will be copied to
+   the output buffer.  In that case, all further file reads will be directly to
+   either the output buffer or a user buffer.  If decompressing, the inflate
+   state and the check value will be initialized.  gz_head() will return 0 on
+   success or -1 on failure.  Failures may include read errors or gzip header
+   errors.  */
+local int gz_head(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+    int flags;
+    unsigned len;
+
+    /* allocate read buffers and inflate memory */
+    if (state->size == 0) {
+        /* allocate buffers */
+        state->in = malloc(state->want);
+        state->out = malloc(state->want << 1);
+        if (state->in == NULL || state->out == NULL) {
+            if (state->out != NULL)
+                free(state->out);
+            if (state->in != NULL)
+                free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        state->size = state->want;
+
+        /* allocate inflate memory */
+        state->strm.zalloc = Z_NULL;
+        state->strm.zfree = Z_NULL;
+        state->strm.opaque = Z_NULL;
+        state->strm.avail_in = 0;
+        state->strm.next_in = Z_NULL;
+        if (inflateInit2(&(state->strm), -15) != Z_OK) {    /* raw inflate */
+            free(state->out);
+            free(state->in);
+            state->size = 0;
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+    }
+
+    /* get some data in the input buffer */
+    if (strm->avail_in == 0) {
+        if (gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0)
+            return 0;
+    }
+
+    /* look for the gzip magic header bytes 31 and 139 */
+    if (strm->next_in[0] == 31) {
+        strm->avail_in--;
+        strm->next_in++;
+        if (strm->avail_in == 0 && gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in && strm->next_in[0] == 139) {
+            /* we have a gzip header, woo hoo! */
+            strm->avail_in--;
+            strm->next_in++;
+
+            /* skip rest of header */
+            if (NEXT() != 8) {      /* compression method */
+                gz_error(state, Z_DATA_ERROR, "unknown compression method");
+                return -1;
+            }
+            flags = NEXT();
+            if (flags & 0xe0) {     /* reserved flag bits */
+                gz_error(state, Z_DATA_ERROR, "unknown header flags set");
+                return -1;
+            }
+            NEXT();                 /* modification time */
+            NEXT();
+            NEXT();
+            NEXT();
+            NEXT();                 /* extra flags */
+            NEXT();                 /* operating system */
+            if (flags & 4) {        /* extra field */
+                len = (unsigned)NEXT();
+                len += (unsigned)NEXT() << 8;
+                while (len--)
+                    if (NEXT() < 0)
+                        break;
+            }
+            if (flags & 8)          /* file name */
+                while (NEXT() > 0)
+                    ;
+            if (flags & 16)         /* comment */
+                while (NEXT() > 0)
+                    ;
+            if (flags & 2) {        /* header crc */
+                NEXT();
+                NEXT();
+            }
+            /* an unexpected end of file is not checked for here -- it will be
+               noticed on the first request for uncompressed data */
+
+            /* set up for decompression */
+            inflateReset(strm);
+            strm->adler = crc32(0L, Z_NULL, 0);
+            state->how = GZIP;
+            state->direct = 0;
+            return 0;
+        }
+        else {
+            /* not a gzip file -- save first byte (31) and fall to raw i/o */
+            state->out[0] = 31;
+            state->have = 1;
+        }
+    }
+
+    /* doing raw i/o, save start of raw data for seeking, copy any leftover
+       input to output -- this assumes that the output buffer is larger than
+       the input buffer, which also assures space for gzungetc() */
+    state->raw = state->pos;
+    state->next = state->out;
+    if (strm->avail_in) {
+        memcpy(state->next + state->have, strm->next_in, strm->avail_in);
+        state->have += strm->avail_in;
+        strm->avail_in = 0;
+    }
+    state->how = COPY;
+    state->direct = 1;
+    return 0;
+}
+
+/* Decompress from input to the provided next_out and avail_out in the state.
+   If the end of the compressed data is reached, then verify the gzip trailer
+   check value and length (modulo 2^32).  state->have and state->next are set
+   to point to the just decompressed data, and the crc is updated.  If the
+   trailer is verified, state->how is reset to LOOK to look for the next gzip
+   stream or raw data, once state->have is depleted.  Returns 0 on success, -1
+   on failure.  Failures may include invalid compressed data or a failed gzip
+   trailer verification. */
+local int gz_decomp(state)
+    gz_statep state;
+{
+    int ret;
+    unsigned had;
+    unsigned long crc, len;
+    z_streamp strm = &(state->strm);
+
+    /* fill output buffer up to end of deflate stream */
+    had = strm->avail_out;
+    do {
+        /* get more input for inflate() */
+        if (strm->avail_in == 0 && gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0) {
+            gz_error(state, Z_DATA_ERROR, "unexpected end of file");
+            return -1;
+        }
+
+        /* decompress and handle errors */
+        ret = inflate(strm, Z_NO_FLUSH);
+        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
+            gz_error(state, Z_STREAM_ERROR,
+                      "internal error: inflate stream corrupt");
+            return -1;
+        }
+        if (ret == Z_MEM_ERROR) {
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */
+            gz_error(state, Z_DATA_ERROR,
+                      strm->msg == NULL ? "compressed data error" : strm->msg);
+            return -1;
+        }
+    } while (strm->avail_out && ret != Z_STREAM_END);
+
+    /* update available output and crc check value */
+    state->have = had - strm->avail_out;
+    state->next = strm->next_out - state->have;
+    strm->adler = crc32(strm->adler, state->next, state->have);
+
+    /* check gzip trailer if at end of deflate stream */
+    if (ret == Z_STREAM_END) {
+        if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
+            gz_error(state, Z_DATA_ERROR, "unexpected end of file");
+            return -1;
+        }
+        if (crc != strm->adler) {
+            gz_error(state, Z_DATA_ERROR, "incorrect data check");
+            return -1;
+        }
+        if (len != (strm->total_out & 0xffffffffL)) {
+            gz_error(state, Z_DATA_ERROR, "incorrect length check");
+            return -1;
+        }
+        state->how = LOOK;      /* ready for next stream, once have is 0 (leave
+                                   state->direct unchanged to remember how) */
+    }
+
+    /* good decompression */
+    return 0;
+}
+
+/* Make data and put in the output buffer.  Assumes that state->have == 0.
+   Data is either copied from the input file or decompressed from the input
+   file depending on state->how.  If state->how is LOOK, then a gzip header is
+   looked for (and skipped if found) to determine wither to copy or decompress.
+   Returns -1 on error, otherwise 0.  gz_make() will leave state->have as COPY
+   or GZIP unless the end of the input file has been reached and all data has
+   been processed.  */
+local int gz_make(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    if (state->how == LOOK) {           /* look for gzip header */
+        if (gz_head(state) == -1)
+            return -1;
+        if (state->have)                /* got some data from gz_head() */
+            return 0;
+    }
+    if (state->how == COPY) {           /* straight copy */
+        if (gz_load(state, state->out, state->size << 1, &(state->have)) == -1)
+            return -1;
+        state->next = state->out;
+    }
+    else if (state->how == GZIP) {      /* decompress */
+        strm->avail_out = state->size << 1;
+        strm->next_out = state->out;
+        if (gz_decomp(state) == -1)
+            return -1;
+    }
+    return 0;
+}
+
+/* Skip len uncompressed bytes of output.  Return -1 on error, 0 on success. */
+local int gz_skip(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    unsigned n;
+
+    /* skip over len bytes or reach end-of-file, whichever comes first */
+    while (len)
+        /* skip over whatever is in output buffer */
+        if (state->have) {
+            n = GT_OFF(state->have) || (z_off64_t)state->have > len ?
+                (unsigned)len : state->have;
+            state->have -= n;
+            state->next += n;
+            state->pos += n;
+            len -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && state->strm.avail_in == 0)
+            break;
+
+        /* need more data to skip -- load up output buffer */
+        else {
+            /* get more output, looking for header if required */
+            if (gz_make(state) == -1)
+                return -1;
+        }
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzread(file, buf, len)
+    gzFile file;
+    voidp buf;
+    unsigned len;
+{
+    unsigned got, n;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids the flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
+        return -1;
+    }
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* get len bytes to buf, or less than len if at the end */
+    got = 0;
+    do {
+        /* first just try copying data from the output buffer */
+        if (state->have) {
+            n = state->have > len ? len : state->have;
+            memcpy(buf, state->next, n);
+            state->next += n;
+            state->have -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && strm->avail_in == 0)
+            break;
+
+        /* need output data -- for small len or new stream load up our output
+           buffer */
+        else if (state->how == LOOK || len < (state->size << 1)) {
+            /* get more output, looking for header if required */
+            if (gz_make(state) == -1)
+                return -1;
+            continue;       /* no progress yet -- go back to memcpy() above */
+            /* the copy above assures that we will leave with space in the
+               output buffer, allowing at least one gzungetc() to succeed */
+        }
+
+        /* large len -- read directly into user buffer */
+        else if (state->how == COPY) {      /* read directly */
+            if (gz_load(state, buf, len, &n) == -1)
+                return -1;
+        }
+
+        /* large len -- decompress directly into user buffer */
+        else {  /* state->how == GZIP */
+            strm->avail_out = len;
+            strm->next_out = buf;
+            if (gz_decomp(state) == -1)
+                return -1;
+            n = state->have;
+            state->have = 0;
+        }
+
+        /* update progress */
+        len -= n;
+        buf = (char *)buf + n;
+        got += n;
+        state->pos += n;
+    } while (len);
+
+    /* return number of bytes read into user buffer (will fit in int) */
+    return (int)got;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzgetc(file)
+    gzFile file;
+{
+    int ret;
+    unsigned char buf[1];
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* try output buffer (no need to check for skip request) */
+    if (state->have) {
+        state->have--;
+        state->pos++;
+        return *(state->next)++;
+    }
+
+    /* nothing there -- try gzread() */
+    ret = gzread(file, buf, 1);
+    return ret < 1 ? -1 : buf[0];
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzungetc(c, file)
+    int c;
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* can't push EOF */
+    if (c < 0)
+        return -1;
+
+    /* if output buffer empty, put byte at end (allows more pushing) */
+    if (state->have == 0) {
+        state->have = 1;
+        state->next = state->out + (state->size << 1) - 1;
+        state->next[0] = c;
+        state->pos--;
+        return c;
+    }
+
+    /* if no room, give up (must have already done a gzungetc()) */
+    if (state->have == (state->size << 1)) {
+        gz_error(state, Z_BUF_ERROR, "out of room to push characters");
+        return -1;
+    }
+
+    /* slide output data if needed and insert byte before existing data */
+    if (state->next == state->out) {
+        unsigned char *src = state->out + state->have;
+        unsigned char *dest = state->out + (state->size << 1);
+        while (src > state->out)
+            *--dest = *--src;
+        state->next = dest;
+    }
+    state->have++;
+    state->next--;
+    state->next[0] = c;
+    state->pos--;
+    return c;
+}
+
+/* -- see zlib.h -- */
+char * ZEXPORT gzgets(file, buf, len)
+    gzFile file;
+    char *buf;
+    int len;
+{
+    unsigned left, n;
+    char *str;
+    unsigned char *eol;
+    gz_statep state;
+
+    /* check parameters and get internal structure */
+    if (file == NULL || buf == NULL || len < 1)
+        return NULL;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return NULL;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return NULL;
+    }
+
+    /* copy output bytes up to new line or len - 1, whichever comes first --
+       append a terminating zero to the string (we don't check for a zero in
+       the contents, let the user worry about that) */
+    str = buf;
+    left = (unsigned)len - 1;
+    if (left) do {
+        /* assure that something is in the output buffer */
+        if (state->have == 0) {
+            if (gz_make(state) == -1)
+                return NULL;            /* error */
+            if (state->have == 0) {     /* end of file */
+                if (buf == str)         /* got bupkus */
+                    return NULL;
+                break;                  /* got something -- return it */
+            }
+        }
+
+        /* look for end-of-line in current output buffer */
+        n = state->have > left ? left : state->have;
+        eol = memchr(state->next, '\n', n);
+        if (eol != NULL)
+            n = (unsigned)(eol - state->next) + 1;
+
+        /* copy through end-of-line, or remainder if not found */
+        memcpy(buf, state->next, n);
+        state->have -= n;
+        state->next += n;
+        state->pos += n;
+        left -= n;
+        buf += n;
+    } while (left && eol == NULL);
+
+    /* found end-of-line or out of space -- terminate string and return it */
+    buf[0] = 0;
+    return str;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzdirect(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return 0;
+
+    /* if the state is not known, but we can find out, then do so (this is
+       mainly for right after a gzopen() or gzdopen()) */
+    if (state->how == LOOK && state->have == 0)
+        (void)gz_head(state);
+
+    /* return 1 if reading direct, 0 if decompressing a gzip stream */
+    return state->direct;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_r(file)
+    gzFile file;
+{
+    int ret;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return Z_STREAM_ERROR;
+
+    /* free memory and close file */
+    if (state->size) {
+        inflateEnd(&(state->strm));
+        free(state->out);
+        free(state->in);
+    }
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    ret = close(state->fd);
+    free(state);
+    return ret ? Z_ERRNO : Z_OK;
+}
diff --git a/gzwrite.c b/gzwrite.c
new file mode 100644
index 000000000..e8defc688
--- /dev/null
+++ b/gzwrite.c
@@ -0,0 +1,531 @@
+/* gzwrite.c -- zlib functions for writing gzip files
+ * Copyright (C) 2004, 2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_init OF((gz_statep));
+local int gz_comp OF((gz_statep, int));
+local int gz_zero OF((gz_statep, z_off64_t));
+
+/* Initialize state for writing a gzip file.  Mark initialization by setting
+   state->size to non-zero.  Return -1 on failure or 0 on success. */
+local int gz_init(state)
+    gz_statep state;
+{
+    int ret;
+    z_streamp strm = &(state->strm);
+
+    /* allocate input and output buffers */
+    state->in = malloc(state->want);
+    state->out = malloc(state->want);
+    if (state->in == NULL || state->out == NULL) {
+        if (state->out != NULL)
+            free(state->out);
+        if (state->in != NULL)
+            free(state->in);
+        gz_error(state, Z_MEM_ERROR, "out of memory");
+        return -1;
+    }
+
+    /* allocate deflate memory, set up for gzip compression */
+    strm->zalloc = Z_NULL;
+    strm->zfree = Z_NULL;
+    strm->opaque = Z_NULL;
+    ret = deflateInit2(strm, state->level, Z_DEFLATED,
+                       15 + 16, 8, state->strategy);
+    if (ret != Z_OK) {
+        free(state->in);
+        gz_error(state, Z_MEM_ERROR, "out of memory");
+        return -1;
+    }
+
+    /* mark state as initialized */
+    state->size = state->want;
+
+    /* initialize write buffer */
+    strm->avail_out = state->size;
+    strm->next_out = state->out;
+    state->next = strm->next_out;
+    return 0;
+}
+
+/* Compress whatever is at avail_in and next_in and write to the output file.
+   Return -1 if there is an error writing to the output file, otherwise 0.
+   flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
+   then the deflate() state is reset to start a new gzip stream. */
+local int gz_comp(state, flush)
+    gz_statep state;
+    int flush;
+{
+    int ret, got;
+    unsigned have;
+    z_streamp strm = &(state->strm);
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return -1;
+
+    /* run deflate() on provided input until it produces no more output */
+    ret = Z_OK;
+    do {
+        /* write out current buffer contents if full, or if flushing, but if
+           doing Z_FINISH then don't write until we get to Z_STREAM_END */
+        if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
+            (flush != Z_FINISH || ret == Z_STREAM_END))) {
+            have = (unsigned)(strm->next_out - state->next);
+            if (have && ((got = write(state->fd, state->next, have)) < 0 ||
+                         (unsigned)got != have)) {
+                gz_error(state, Z_ERRNO, zstrerror());
+                return -1;
+            }
+            if (strm->avail_out == 0) {
+                strm->avail_out = state->size;
+                strm->next_out = state->out;
+            }
+            state->next = strm->next_out;
+        }
+
+        /* compress */
+        have = strm->avail_out;
+        ret = deflate(strm, flush);
+        if (ret == Z_STREAM_ERROR) {
+            gz_error(state, Z_STREAM_ERROR,
+                      "internal error: deflate stream corrupt");
+            return -1;
+        }
+        have -= strm->avail_out;
+    } while (have);
+
+    /* if that completed a deflate stream, allow another to start */
+    if (flush == Z_FINISH)
+        deflateReset(strm);
+
+    /* all done, no errors */
+    return 0;
+}
+
+/* Compress len zeros to output.  Return -1 on error, 0 on success. */
+local int gz_zero(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    int first;
+    unsigned n;
+    z_streamp strm = &(state->strm);
+
+    /* consume whatever's left in the input buffer */
+    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+        return -1;
+
+    /* compress len zeros (len guaranteed > 0) */
+    first = 1;
+    while (len) {
+        n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
+            (unsigned)len : state->size;
+        if (first) {
+            memset(state->in, 0, n);
+            first = 0;
+        }
+        strm->avail_in = n;
+        strm->next_in = state->in;
+        state->pos += n;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return -1;
+        len -= n;
+    }
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzwrite(file, buf, len)
+    gzFile file;
+    voidpc buf;
+    unsigned len;
+{
+    unsigned put = len;
+    unsigned n;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids the flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_BUF_ERROR, "requested length does not fit in int");
+        return 0;
+    }
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return 0;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* for small len, copy to input buffer, otherwise compress directly */
+    if (len < state->size) {
+        /* copy to input buffer, compress when full */
+        do {
+            if (strm->avail_in == 0)
+                strm->next_in = state->in;
+            n = state->size - strm->avail_in;
+            if (n > len)
+                n = len;
+            memcpy(strm->next_in + strm->avail_in, buf, n);
+            strm->avail_in += n;
+            state->pos += n;
+            buf = (char *)buf + n;
+            len -= n;
+            if (len && gz_comp(state, Z_NO_FLUSH) == -1)
+                return 0;
+        } while (len);
+    }
+    else {
+        /* consume whatever's left in the input buffer */
+        if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+            return 0;
+
+        /* directly compress user buffer to file */
+        strm->avail_in = len;
+        strm->next_in = (voidp)buf;
+        state->pos += len;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return 0;
+    }
+
+    /* input was all buffered or compressed (put will fit in int) */
+    return (int)put;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputc(file, c)
+    gzFile file;
+    int c;
+{
+    unsigned char buf[1];
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return -1;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* try writing to input buffer for speed (state->size == 0 if buffer not
+       initialized) */
+    if (strm->avail_in < state->size) {
+        if (strm->avail_in == 0)
+            strm->next_in = state->in;
+        strm->next_in[strm->avail_in++] = c;
+        state->pos++;
+        return c;
+    }
+
+    /* no room in buffer or not initialized, use gz_write() */
+    buf[0] = c;
+    if (gzwrite(file, buf, 1) != 1)
+        return -1;
+    return c;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputs(file, str)
+    gzFile file;
+    const char *str;
+{
+    int ret;
+    unsigned len;
+
+    /* write string */
+    len = (unsigned)strlen(str);
+    ret = gzwrite(file, str, len);
+    return ret == 0 && len != 0 ? -1 : ret;
+}
+
+#ifdef STDC
+#include <stdarg.h>
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzprintf (gzFile file, const char *format, ...)
+{
+    int size, len;
+    gz_statep state;
+    z_streamp strm;
+    va_list va;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return 0;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* consume whatever's left in the input buffer */
+    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+        return 0;
+
+    /* do the printf() into the input buffer, put length in len */
+    size = (int)(state->size);
+    state->in[size - 1] = 0;
+    va_start(va, format);
+#ifdef NO_vsnprintf
+#  ifdef HAS_vsprintf_void
+    (void)vsprintf(state->in, format, va);
+    va_end(va);
+    for (len = 0; len < size; len++)
+        if (state->in[len] == 0) break;
+#  else
+    len = vsprintf(state->in, format, va);
+    va_end(va);
+#  endif
+#else
+#  ifdef HAS_vsnprintf_void
+    (void)vsnprintf(state->in, size, format, va);
+    va_end(va);
+    len = strlen(state->in);
+#  else
+    len = vsnprintf((char *)(state->in), size, format, va);
+    va_end(va);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, defer compression until needed */
+    strm->avail_in = (unsigned)len;
+    strm->next_in = state->in;
+    state->pos += len;
+    return len;
+}
+
+#else /* !STDC */
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+                       a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
+    gzFile file;
+    const char *format;
+    int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
+{
+    int size, len;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return 0;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* consume whatever's left in the input buffer */
+    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+        return 0;
+
+    /* do the printf() into the input buffer, put length in len */
+    size = (int)(state->size);
+    state->in[size - 1] = 0;
+#ifdef NO_snprintf
+#  ifdef HAS_sprintf_void
+    sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
+            a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+    for (len = 0; len < size; len++)
+        if (state->in[len] == 0) break;
+#  else
+    len = sprintf(state->in, format, a1, a2, a3, a4, a5, a6, a7, a8,
+                a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#else
+#  ifdef HAS_snprintf_void
+    snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
+             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+    len = strlen(state->in);
+#  else
+    len = snprintf(state->in, size, format, a1, a2, a3, a4, a5, a6, a7, a8,
+                 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, defer compression until needed */
+    strm->avail_in = (unsigned)len;
+    strm->next_in = state->in;
+    state->pos += len;
+    return len;
+}
+
+#endif
+
+/* -- see zlib.h -- */
+int ZEXPORT gzflush(file, flush)
+    gzFile file;
+    int flush;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* check flush parameter */
+    if (flush < 0 || flush > Z_FINISH)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* compress remaining data with requested flush */
+    gz_comp(state, flush);
+    return state->err;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzsetparams(file, level, strategy)
+    gzFile file;
+    int level;
+    int strategy;
+{
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* if no change is requested, then do nothing */
+    if (level == state->level && strategy == state->strategy)
+        return Z_OK;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* change compression parameters for subsequent input */
+    if (state->size) {
+        /* flush previous input with previous parameters before changing */
+        if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
+            return state->err;
+        deflateParams(strm, level, strategy);
+    }
+    state->level = level;
+    state->strategy = strategy;
+    return Z_OK;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_w(file)
+    gzFile file;
+{
+    int ret = 0;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're writing */
+    if (state->mode != GZ_WRITE)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        ret += gz_zero(state, state->skip);
+    }
+
+    /* flush, free memory, and close file */
+    ret += gz_comp(state, Z_FINISH);
+    (void)deflateEnd(&(state->strm));
+    free(state->out);
+    free(state->in);
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    ret += close(state->fd);
+    free(state);
+    return ret ? Z_ERRNO : Z_OK;
+}
diff --git a/inffast.c b/inffast.c
index 0a0761f3d..2f1d60b43 100644
--- a/inffast.c
+++ b/inffast.c
@@ -1,5 +1,5 @@
 /* inffast.c -- fast decoding
- * Copyright (C) 1995-2008 Mark Adler
+ * Copyright (C) 1995-2008, 2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -64,7 +64,7 @@
       requires strm->avail_out >= 258 for each loop to avoid checking for
       output space.
  */
-void inflate_fast(strm, start)
+void ZLIB_INTERNAL inflate_fast(strm, start)
 z_streamp strm;
 unsigned start;         /* inflate()'s starting value for strm->avail_out */
 {
diff --git a/inffast.h b/inffast.h
index 1e88d2d97..e5c1aa4ca 100644
--- a/inffast.h
+++ b/inffast.h
@@ -1,5 +1,5 @@
 /* inffast.h -- header to use inffast.c
- * Copyright (C) 1995-2003 Mark Adler
+ * Copyright (C) 1995-2003, 2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -8,4 +8,4 @@
    subject to change. Applications should only use zlib.h.
  */
 
-void inflate_fast OF((z_streamp strm, unsigned start));
+void ZLIB_INTERNAL inflate_fast OF((z_streamp strm, unsigned start));
diff --git a/inftrees.c b/inftrees.c
index 3ee7d0636..11e9c52ac 100644
--- a/inftrees.c
+++ b/inftrees.c
@@ -9,7 +9,7 @@
 #define MAXBITS 15
 
 const char inflate_copyright[] =
-   " inflate 1.2.4 Copyright 1995-2010 Mark Adler ";
+   " inflate 1.2.5 Copyright 1995-2010 Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
@@ -29,7 +29,7 @@ const char inflate_copyright[] =
    table index bits.  It will differ if the request is greater than the
    longest code or if it is less than the shortest code.
  */
-int inflate_table(type, lens, codes, table, bits, work)
+int ZLIB_INTERNAL inflate_table(type, lens, codes, table, bits, work)
 codetype type;
 unsigned short FAR *lens;
 unsigned codes;
@@ -62,7 +62,7 @@ unsigned short FAR *work;
         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
     static const unsigned short lext[31] = { /* Length codes 257..285 extra */
         16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
-        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 66, 199};
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 73, 195};
     static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
diff --git a/inftrees.h b/inftrees.h
index 67461da03..baa53a0b1 100644
--- a/inftrees.h
+++ b/inftrees.h
@@ -1,5 +1,5 @@
 /* inftrees.h -- header to use inftrees.c
- * Copyright (C) 1995-2005 Mark Adler
+ * Copyright (C) 1995-2005, 2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -57,6 +57,6 @@ typedef enum {
     DISTS
 } codetype;
 
-extern int inflate_table OF((codetype type, unsigned short FAR *lens,
+int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens,
                              unsigned codes, code FAR * FAR *table,
                              unsigned FAR *bits, unsigned short FAR *work));
diff --git a/png.c b/png.c
index 83b4ca2ea..004e41529 100644
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Last changed in libpng 1.4.2 [May 6, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -17,7 +17,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_4_1 Your_png_h_is_not_version_1_4_1;
+typedef version_1_4_2 Your_png_h_is_not_version_1_4_2;
 
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
@@ -551,13 +551,13 @@ png_get_copyright(png_structp png_ptr)
 #else
 #ifdef __STDC__
    return ((png_charp) PNG_STRING_NEWLINE \
-     "libpng version 1.4.1 - February 25, 2010" PNG_STRING_NEWLINE \
+     "libpng version 1.4.2 - May 6, 2010" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE);
 #else
-      return ((png_charp) "libpng version 1.4.1 - February 25, 2010\
+      return ((png_charp) "libpng version 1.4.2 - May 6, 2010\
       Copyright (c) 1998-2010 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
@@ -622,7 +622,9 @@ png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
    return 0;
 }
 #endif
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 
+#ifdef PNG_READ_SUPPORTED
 /* This function, added to libpng-1.0.6g, is untested. */
 int PNGAPI
 png_reset_zstream(png_structp png_ptr)
@@ -631,7 +633,7 @@ png_reset_zstream(png_structp png_ptr)
       return Z_STREAM_ERROR;
    return (inflateReset(&png_ptr->zstream));
 }
-#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+#endif /* PNG_READ_SUPPORTED */
 
 /* This function was added to libpng-1.0.7 */
 png_uint_32 PNGAPI
diff --git a/png.h b/png.h
index c48dcdb97..de0843aae 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.4.1 - February 25, 2010
+ * libpng version 1.4.2 - May 6, 2010
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *  libpng versions 0.97, January 1998, through 1.4.1 - February 25, 2010: Glenn
+ *  libpng versions 0.97, January 1998, through 1.4.2 - May 6, 2010: Glenn
  *  See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -139,6 +139,9 @@
  *    1.4.1beta04-12          14    10401  14.so.14.1[.0]
  *    1.4.1rc02-04            14    10401  14.so.14.1[.0]
  *    1.4.1                   14    10401  14.so.14.1[.0]
+ *    1.4.2beta01             14    10402  14.so.14.2[.0]
+ *    1.4.2rc02-06            14    10402  14.so.14.2[.0]
+ *    1.4.2                   14    10402  14.so.14.2[.0]
  *
  *    Henceforth the source version will match the shared-library major
  *    and minor numbers; the shared-library major version number will be
@@ -170,7 +173,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.4.1, February 25, 2010, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.4.2, May 6, 2010, are
  * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -282,13 +285,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    February 25, 2010
+ *    May 6, 2010
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.4.1 are Y2K compliant.  It is my belief that earlier
+ *    upward through 1.4.2 are Y2K compliant.  It is my belief that earlier
  *    versions were also Y2K compliant.
  *
  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
@@ -344,9 +347,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.4.1"
+#define PNG_LIBPNG_VER_STRING "1.4.2"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.4.1 - February 25, 2010\n"
+   " libpng version 1.4.2 - May 6, 2010\n"
 
 #define PNG_LIBPNG_VER_SONUM   14
 #define PNG_LIBPNG_VER_DLLNUM  14
@@ -354,7 +357,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   4
-#define PNG_LIBPNG_VER_RELEASE 1
+#define PNG_LIBPNG_VER_RELEASE 2
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
@@ -384,7 +387,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10401 /* 1.4.1 */
+#define PNG_LIBPNG_VER 10402 /* 1.4.2 */
 
 #ifndef PNG_VERSION_INFO_ONLY
 /* Include the compression library's header */
@@ -1332,13 +1335,13 @@ struct png_struct_def
    png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-   png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
-   png_bytep dither_index PNG_DEPSTRUCT;   /* index translation for palette
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for quantizing */
+   png_bytep quantize_index PNG_DEPSTRUCT; /* index translation for palette
                                               files */
 #endif
 
-#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
+#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
    png_uint_16p hist PNG_DEPSTRUCT;                /* histogram */
 #endif
 
@@ -1422,9 +1425,9 @@ struct png_struct_def
    png_bytep big_row_buf PNG_DEPSTRUCT;         /* buffer to save current
                                                    (unfiltered) row */
 
-#ifdef PNG_READ_DITHER_SUPPORTED
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
 /* The following three members were added at version 1.0.14 and 1.2.4 */
-   png_bytep dither_sort PNG_DEPSTRUCT;            /* working sort array */
+   png_bytep quantize_sort PNG_DEPSTRUCT;          /* working sort array */
    png_bytep index_to_palette PNG_DEPSTRUCT;       /* where the original
                                                      index currently is
                                                      in the palette */
@@ -1468,7 +1471,7 @@ struct png_struct_def
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef png_structp version_1_4_1;
+typedef png_structp version_1_4_2;
 
 typedef png_struct FAR * FAR * png_structpp;
 
@@ -1495,6 +1498,11 @@ extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
    png_size_t num_to_check));
 
+/* Simple signature checking function.  This is the same as calling
+ * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
+ */
+#define png_check_sig(sig,n) !png_sig_cmp((sig), 0, (n))
+
 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
 extern PNG_EXPORT(png_structp,png_create_read_struct)
    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
@@ -1532,8 +1540,10 @@ extern PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
    (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
 #endif
 
+#ifdef PNG_READ_SUPPORTED
 /* Reset the compression stream */
 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
+#endif
 
 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -1710,14 +1720,16 @@ extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-/* Turn on dithering, and reduce the palette to the number of colors
- * available.
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Turn on quantizing, and reduce the palette to the number of colors
+ * available.  Prior to libpng-1.4.2, this was png_set_dither().
  */
-extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
+extern PNG_EXPORT(void,png_set_quantize) PNGARG((png_structp png_ptr,
    png_colorp palette, int num_palette, int maximum_colors,
-   png_uint_16p histogram, int full_dither));
+   png_uint_16p histogram, int full_quantize));
 #endif
+/* This migration aid will be removed from libpng-1.5.0 */
+#define png_set_dither png_set_quantize
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 /* Handle gamma correction. Screen_gamma=(display_exponent) */
diff --git a/pngconf.h b/pngconf.h
index 584a22594..9cc8e781a 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.4.1 - February 25, 2010
+ * libpng version 1.4.2 - May 6, 2010
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -14,6 +14,7 @@
  * This file has been modified, by Glenn Randers-Pehrson, from the original
  * libpng distribution by adding a line reading
  * #include "pngcrush.h"
+ *
  */
 
 /* Any machine specific code is near the front of this file, so if you
@@ -396,18 +397,32 @@
 
 /* Other defines for things like memory and the like can go here.  */
 
-/* This controls how fine the dithering gets.  As this allocates
+/* This controls how fine the quantizing gets.  As this allocates
  * a largish chunk of memory (32K), those who are not as concerned
- * with dithering quality can decrease some or all of these.
+ * with quantizing quality can decrease some or all of these.
+ */
+
+/* Prior to libpng-1.4.2, these were PNG_DITHER_*_BITS
+ * These migration aids will be removed from libpng-1.5.0.
  */
-#ifndef PNG_DITHER_RED_BITS
-#  define PNG_DITHER_RED_BITS 5
+#ifdef PNG_DITHER_RED_BITS
+#  define PNG_QUANTIZE_RED_BITS PNG_DITHER_RED_BITS
+#endif
+#ifdef PNG_DITHER_GREEN_BITS
+#  define PNG_QUANTIZE_GREEN_BITS PNG_DITHER_GREEN_BITS
 #endif
-#ifndef PNG_DITHER_GREEN_BITS
-#  define PNG_DITHER_GREEN_BITS 5
+#ifdef PNG_DITHER_BLUE_BITS
+#  define PNG_QUANTIZE_BLUE_BITS PNG_DITHER_BLUE_BITS
 #endif
-#ifndef PNG_DITHER_BLUE_BITS
-#  define PNG_DITHER_BLUE_BITS 5
+
+#ifndef PNG_QUANTIZE_RED_BITS
+#  define PNG_QUANTIZE_RED_BITS 5
+#endif
+#ifndef PNG_QUANTIZE_GREEN_BITS
+#  define PNG_QUANTIZE_GREEN_BITS 5
+#endif
+#ifndef PNG_QUANTIZE_BLUE_BITS
+#  define PNG_QUANTIZE_BLUE_BITS 5
 #endif
 
 /* This controls how fine the gamma correction becomes when you
@@ -504,11 +519,12 @@
 #  ifndef PNG_NO_READ_INVERT
 #    define PNG_READ_INVERT_SUPPORTED
 #  endif
-#if 0 /* removed from libpng-1.4.0 */
-#  ifndef PNG_NO_READ_DITHER
-#    define PNG_READ_DITHER_SUPPORTED
+#  ifndef PNG_NO_READ_QUANTIZE
+     /* Prior to libpng-1.4.0 this was PNG_READ_DITHER_SUPPORTED */
+#    ifndef PNG_NO_READ_DITHER  /* This migration aid will be removed */
+#      define PNG_READ_QUANTIZE_SUPPORTED
+#    endif
 #  endif
-#endif /* 0 */
 #  ifndef PNG_NO_READ_BACKGROUND
 #    define PNG_READ_BACKGROUND_SUPPORTED
 #  endif
diff --git a/pngcrush.c b/pngcrush.c
index 29d819024..07e35a090 100644
--- a/pngcrush.c
+++ b/pngcrush.c
@@ -57,7 +57,7 @@
  *
  */
 
-#define PNGCRUSH_VERSION "1.7.10"
+#define PNGCRUSH_VERSION "1.7.11"
 
 /*
 #define PNGCRUSH_COUNT_COLORS
@@ -160,6 +160,8 @@
 
 Change log:
 
+Version 1.7.11  (built with libpng-1.4.2 and zlib-1.2.5)
+
 Version 1.7.10  (built with libpng-1.4.1 and zlib-1.2.3.9)
   Added missing "(...)" in png_get_uint_32().
   Only compile png_get_uint_32(), etc., when PNG_LIBPNG_VER < 1.2.9
@@ -4970,7 +4972,7 @@ int main(int argc, char *argv[])
                         png_free(write_ptr, unknowns_keep);
                     }
                 }
-              P0("unknown chunk handling done.\n");
+              P1("unknown chunk handling done.\n");
 #endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
 
                 /* } GRR added for quick %-navigation (1) */
diff --git a/pngget.c b/pngget.c
index ea36f25bc..abe721bd5 100644
--- a/pngget.c
+++ b/pngget.c
@@ -1,7 +1,7 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Last changed in libpng 1.4.2 [May 6, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngmem.c b/pngmem.c
index 279ba6335..c8a3f6f59 100644
--- a/pngmem.c
+++ b/pngmem.c
@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.4.0 [February 25, 2010]
+ * Last changed in libpng 1.4.2 [May 6, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngpriv.h b/pngpriv.h
index 8e8477c05..a7eb776ed 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -1,7 +1,7 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * libpng version 1.4.1 - February 25, 2010
+ * libpng version 1.4.2 - May 6, 2010
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -106,7 +106,7 @@
 #define PNG_SHIFT               0x0008
 #define PNG_SWAP_BYTES          0x0010
 #define PNG_INVERT_MONO         0x0020
-#define PNG_DITHER              0x0040
+#define PNG_QUANTIZE            0x0040 /* formerly PNG_DITHER */
 #define PNG_BACKGROUND          0x0080
 #define PNG_BACKGROUND_EXPAND   0x0100
                           /*    0x0200 unused */
@@ -588,9 +588,9 @@ PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
-   png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
+   png_bytep row, png_bytep palette_lookup, png_bytep quantize_lookup));
 
 #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
diff --git a/pngread.c b/pngread.c
index 97803f2c5..92060d2bc 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1080,9 +1080,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_free(png_ptr, png_ptr->big_row_buf);
    png_free(png_ptr, png_ptr->prev_row);
    png_free(png_ptr, png_ptr->chunkdata);
-#ifdef PNG_READ_DITHER_SUPPORTED
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
    png_free(png_ptr, png_ptr->palette_lookup);
-   png_free(png_ptr, png_ptr->dither_index);
+   png_free(png_ptr, png_ptr->quantize_index);
 #endif
 #ifdef PNG_READ_GAMMA_SUPPORTED
    png_free(png_ptr, png_ptr->gamma_table);
@@ -1257,7 +1257,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
          png_set_expand(png_ptr);
 #endif
 
-   /* We don't handle background color or gamma transformation or dithering.
+   /* We don't handle background color or gamma transformation or quantizing.
     */
 
 #ifdef PNG_READ_INVERT_SUPPORTED
diff --git a/pngrtran.c b/pngrtran.c
index c7e521517..b5e8f1a26 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.4.1 [February 25, 2010]
+ * Last changed in libpng 1.4.2 [May 6, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -141,13 +141,13 @@ png_set_strip_alpha(png_structp png_ptr)
 }
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-/* Dither file to 8 bit.  Supply a palette, the current number
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Quantize file to 8 bit.  Supply a palette, the current number
  * of elements in the palette, the maximum number of elements
  * allowed, and a histogram if possible.  If the current number
  * of colors is greater then the maximum number, the palette will be
- * modified to fit in the maximum number.  "full_dither" indicates
- * whether we need a dithering cube set up for RGB images, or if we
+ * modified to fit in the maximum number.  "full_quantize" indicates
+ * whether we need a quantizeing cube set up for RGB images, or if we
  * simply are reducing the number of colors in a paletted image.
  */
 
@@ -161,24 +161,24 @@ typedef png_dsort FAR *       png_dsortp;
 typedef png_dsort FAR * FAR * png_dsortpp;
 
 void PNGAPI
-png_set_dither(png_structp png_ptr, png_colorp palette,
+png_set_quantize(png_structp png_ptr, png_colorp palette,
    int num_palette, int maximum_colors, png_uint_16p histogram,
-   int full_dither)
+   int full_quantize)
 {
-   png_debug(1, "in png_set_dither");
+   png_debug(1, "in png_set_quantize");
 
    if (png_ptr == NULL)
       return;
-   png_ptr->transformations |= PNG_DITHER;
+   png_ptr->transformations |= PNG_QUANTIZE;
 
-   if (!full_dither)
+   if (!full_quantize)
    {
       int i;
 
-      png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
+      png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
          (png_uint_32)(num_palette * png_sizeof(png_byte)));
       for (i = 0; i < num_palette; i++)
-         png_ptr->dither_index[i] = (png_byte)i;
+         png_ptr->quantize_index[i] = (png_byte)i;
    }
 
    if (num_palette > maximum_colors)
@@ -192,12 +192,12 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
          int i;
 
          /* Initialize an array to sort colors */
-         png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
+         png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
             (png_uint_32)(num_palette * png_sizeof(png_byte)));
 
-         /* Initialize the dither_sort array */
+         /* Initialize the quantize_sort array */
          for (i = 0; i < num_palette; i++)
-            png_ptr->dither_sort[i] = (png_byte)i;
+            png_ptr->quantize_sort[i] = (png_byte)i;
 
          /* Find the least used palette entries by starting a
           * bubble sort, and running it until we have sorted
@@ -214,14 +214,14 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             done = 1;
             for (j = 0; j < i; j++)
             {
-               if (histogram[png_ptr->dither_sort[j]]
-                   < histogram[png_ptr->dither_sort[j + 1]])
+               if (histogram[png_ptr->quantize_sort[j]]
+                   < histogram[png_ptr->quantize_sort[j + 1]])
                {
                   png_byte t;
 
-                  t = png_ptr->dither_sort[j];
-                  png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
-                  png_ptr->dither_sort[j + 1] = t;
+                  t = png_ptr->quantize_sort[j];
+                  png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+                  png_ptr->quantize_sort[j + 1] = t;
                   done = 0;
                }
             }
@@ -230,7 +230,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
          }
 
          /* Swap the palette around, and set up a table, if necessary */
-         if (full_dither)
+         if (full_quantize)
          {
             int j = num_palette;
 
@@ -239,11 +239,11 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
              */
             for (i = 0; i < maximum_colors; i++)
             {
-               if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
                {
                   do
                      j--;
-                  while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
                   palette[i] = palette[j];
                }
             }
@@ -258,32 +258,32 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             for (i = 0; i < maximum_colors; i++)
             {
                /* Only move the colors we need to */
-               if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
                {
                   png_color tmp_color;
 
                   do
                      j--;
-                  while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
 
                   tmp_color = palette[j];
                   palette[j] = palette[i];
                   palette[i] = tmp_color;
                   /* Indicate where the color went */
-                  png_ptr->dither_index[j] = (png_byte)i;
-                  png_ptr->dither_index[i] = (png_byte)j;
+                  png_ptr->quantize_index[j] = (png_byte)i;
+                  png_ptr->quantize_index[i] = (png_byte)j;
                }
             }
 
             /* Find closest color for those colors we are not using */
             for (i = 0; i < num_palette; i++)
             {
-               if ((int)png_ptr->dither_index[i] >= maximum_colors)
+               if ((int)png_ptr->quantize_index[i] >= maximum_colors)
                {
                   int min_d, k, min_k, d_index;
 
                   /* Find the closest color to one we threw out */
-                  d_index = png_ptr->dither_index[i];
+                  d_index = png_ptr->quantize_index[i];
                   min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
                   for (k = 1, min_k = 0; k < maximum_colors; k++)
                   {
@@ -298,12 +298,12 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
                      }
                   }
                   /* Point to closest color */
-                  png_ptr->dither_index[i] = (png_byte)min_k;
+                  png_ptr->quantize_index[i] = (png_byte)min_k;
                }
             }
          }
-         png_free(png_ptr, png_ptr->dither_sort);
-         png_ptr->dither_sort = NULL;
+         png_free(png_ptr, png_ptr->quantize_sort);
+         png_ptr->quantize_sort = NULL;
       }
       else
       {
@@ -410,19 +410,19 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
                         num_new_palette--;
                         palette[png_ptr->index_to_palette[j]]
                           = palette[num_new_palette];
-                        if (!full_dither)
+                        if (!full_quantize)
                         {
                            int k;
 
                            for (k = 0; k < num_palette; k++)
                            {
-                              if (png_ptr->dither_index[k] ==
+                              if (png_ptr->quantize_index[k] ==
                                  png_ptr->index_to_palette[j])
-                                 png_ptr->dither_index[k] =
+                                 png_ptr->quantize_index[k] =
                                     png_ptr->index_to_palette[next_j];
-                              if ((int)png_ptr->dither_index[k] ==
+                              if ((int)png_ptr->quantize_index[k] ==
                                  num_new_palette)
-                                 png_ptr->dither_index[k] =
+                                 png_ptr->quantize_index[k] =
                                     png_ptr->index_to_palette[j];
                            }
                         }
@@ -475,15 +475,15 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
    }
    png_ptr->num_palette = (png_uint_16)num_palette;
 
-   if (full_dither)
+   if (full_quantize)
    {
       int i;
       png_bytep distance;
-      int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
-         PNG_DITHER_BLUE_BITS;
-      int num_red = (1 << PNG_DITHER_RED_BITS);
-      int num_green = (1 << PNG_DITHER_GREEN_BITS);
-      int num_blue = (1 << PNG_DITHER_BLUE_BITS);
+      int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+         PNG_QUANTIZE_BLUE_BITS;
+      int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+      int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+      int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
       png_size_t num_entries = ((png_size_t)1 << total_bits);
 
       png_ptr->palette_lookup = (png_bytep )png_calloc(png_ptr,
@@ -496,16 +496,16 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
       for (i = 0; i < num_palette; i++)
       {
          int ir, ig, ib;
-         int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
-         int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
-         int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
+         int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+         int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+         int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
 
          for (ir = 0; ir < num_red; ir++)
          {
             /* int dr = abs(ir - r); */
             int dr = ((ir > r) ? ir - r : r - ir);
-            int index_r = (ir << (PNG_DITHER_BLUE_BITS +
-                PNG_DITHER_GREEN_BITS));
+            int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+                PNG_QUANTIZE_GREEN_BITS));
 
             for (ig = 0; ig < num_green; ig++)
             {
@@ -513,7 +513,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
                int dg = ((ig > g) ? ig - g : g - ig);
                int dt = dr + dg;
                int dm = ((dr > dg) ? dr : dg);
-               int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
+               int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
 
                for (ib = 0; ib < num_blue; ib++)
                {
@@ -536,7 +536,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
       png_free(png_ptr, distance);
    }
 }
-#endif
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
 
 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
 /* Transform the image from the file_gamma to the screen_gamma.  We
@@ -1229,8 +1229,8 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
       info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-   if (png_ptr->transformations & PNG_DITHER)
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if (png_ptr->transformations & PNG_QUANTIZE)
    {
       if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
           (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
@@ -1451,13 +1451,13 @@ png_do_read_transformations(png_structp png_ptr)
       png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
-   if (png_ptr->transformations & PNG_DITHER)
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if (png_ptr->transformations & PNG_QUANTIZE)
    {
-      png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
-         png_ptr->palette_lookup, png_ptr->dither_index);
+      png_do_quantize((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
+         png_ptr->palette_lookup, png_ptr->quantize_index);
       if (png_ptr->row_info.rowbytes == (png_uint_32)0)
-         png_error(png_ptr, "png_do_dither returned rowbytes=0");
+         png_error(png_ptr, "png_do_quantize returned rowbytes=0");
    }
 #endif
 
@@ -3790,16 +3790,16 @@ png_do_expand(png_row_infop row_info, png_bytep row,
 }
 #endif
 
-#ifdef PNG_READ_DITHER_SUPPORTED
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
 void /* PRIVATE */
-png_do_dither(png_row_infop row_info, png_bytep row,
-    png_bytep palette_lookup, png_bytep dither_lookup)
+png_do_quantize(png_row_infop row_info, png_bytep row,
+    png_bytep palette_lookup, png_bytep quantize_lookup)
 {
    png_bytep sp, dp;
    png_uint_32 i;
    png_uint_32 row_width=row_info->width;
 
-   png_debug(1, "in png_do_dither");
+   png_debug(1, "in png_do_quantize");
 
    {
       if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
@@ -3821,14 +3821,14 @@ png_do_dither(png_row_infop row_info, png_bytep row,
              *    (((g >> 3) & 0x1f) << 5) |
              *    ((b >> 3) & 0x1f);
              */
-            p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
-               ((1 << PNG_DITHER_RED_BITS) - 1)) <<
-               (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
-               (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
-               ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
-               (PNG_DITHER_BLUE_BITS)) |
-               ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
-               ((1 << PNG_DITHER_BLUE_BITS) - 1));
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+               ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+               (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+               (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+               ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+               (PNG_QUANTIZE_BLUE_BITS)) |
+               ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+               ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
 
             *dp++ = palette_lookup[p];
          }
@@ -3850,14 +3850,14 @@ png_do_dither(png_row_infop row_info, png_bytep row,
             b = *sp++;
             sp++;
 
-            p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
-               ((1 << PNG_DITHER_RED_BITS) - 1)) <<
-               (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
-               (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
-               ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
-               (PNG_DITHER_BLUE_BITS)) |
-               ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
-               ((1 << PNG_DITHER_BLUE_BITS) - 1));
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+               ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+               (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+               (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+               ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+               (PNG_QUANTIZE_BLUE_BITS)) |
+               ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+               ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
 
             *dp++ = palette_lookup[p];
          }
@@ -3867,12 +3867,12 @@ png_do_dither(png_row_infop row_info, png_bytep row,
          row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
       }
       else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
-         dither_lookup && row_info->bit_depth == 8)
+         quantize_lookup && row_info->bit_depth == 8)
       {
          sp = row;
          for (i = 0; i < row_width; i++, sp++)
          {
-            *sp = dither_lookup[*sp];
+            *sp = quantize_lookup[*sp];
          }
       }
    }
diff --git a/pngrutil.c b/pngrutil.c
index 64aa961e0..2fc3ac289 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -33,11 +33,10 @@ png_get_uint_31(png_structp png_ptr, png_bytep buf)
 png_uint_32 PNGAPI
 png_get_uint_32(png_bytep buf)
 {
-   png_uint_32 i =
-      ((png_uint_32)(*(buf    )) << 24) +
+   png_uint_32 i = ((png_uint_32)(*buf) << 24) +
       ((png_uint_32)(*(buf + 1)) << 16) +
-      ((png_uint_32)(*(buf + 2)) <<  8) +
-      ((png_uint_32)(*(buf + 3))      ) ;
+      ((png_uint_32)(*(buf + 2)) << 8) +
+      (png_uint_32)(*(buf + 3));
 
    return (i);
 }
@@ -204,7 +203,7 @@ png_crc_error(png_structp png_ptr)
     defined(PNG_READ_iCCP_SUPPORTED)
 static png_size_t
 png_inflate(png_structp png_ptr, const png_byte *data, png_size_t size,
-	png_bytep output, png_size_t output_size)
+        png_bytep output, png_size_t output_size)
 {
    png_size_t count = 0;
 
@@ -230,11 +229,11 @@ png_inflate(png_structp png_ptr, const png_byte *data, png_size_t size,
       if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
       {
          if (output != 0 && output_size > count)
-	 {
-	    int copy = output_size - count;
-	    if (avail < copy) copy = avail;
-	    png_memcpy(output + count, png_ptr->zbuf, copy);
-	 }
+         {
+            int copy = output_size - count;
+            if (avail < copy) copy = avail;
+            png_memcpy(output + count, png_ptr->zbuf, copy);
+         }
          count += avail;
       }
 
@@ -255,31 +254,33 @@ png_inflate(png_structp png_ptr, const png_byte *data, png_size_t size,
        * buffer if available.
        */
       {
-         char *msg, umsg[52];
-	 if (png_ptr->zstream.msg != 0)
-	    msg = png_ptr->zstream.msg;
-	 else
-	 {
+         char *msg;
+         if (png_ptr->zstream.msg != 0)
+            msg = png_ptr->zstream.msg;
+         else
+         {
 #ifdef PNG_STDIO_SUPPORTED
-	    switch (ret)
-	    {
-	 case Z_BUF_ERROR:
-	    msg = "Buffer error in compressed datastream in %s chunk";
-	    break;
-	 case Z_DATA_ERROR:
-	    msg = "Data error in compressed datastream in %s chunk";
-	    break;
-	 default:
-	    msg = "Incomplete compressed datastream in %s chunk";
-	    break;
-	    }
-
-	    png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
-	    msg = umsg;
+            char umsg[52];
+
+            switch (ret)
+            {
+               case Z_BUF_ERROR:
+                  msg = "Buffer error in compressed datastream in %s chunk";
+                  break;
+               case Z_DATA_ERROR:
+                  msg = "Data error in compressed datastream in %s chunk";
+                  break;
+               default:
+                  msg = "Incomplete compressed datastream in %s chunk";
+                  break;
+            }
+
+            png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
+            msg = umsg;
 #else
-	    msg = "Damaged compressed datastream in chunk other than IDAT";
+            msg = "Damaged compressed datastream in chunk other than IDAT";
 #endif
-	 }
+         }
 
          png_warning(png_ptr, msg);
       }
@@ -314,9 +315,9 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
    else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
    {
       png_size_t expanded_size = png_inflate(png_ptr,
-		(png_bytep)(png_ptr->chunkdata + prefix_size),
+                (png_bytep)(png_ptr->chunkdata + prefix_size),
                 chunklength - prefix_size,
-		0/*output*/, 0/*output size*/);
+                0/*output*/, 0/*output size*/);
 
       /* Now check the limits on this chunk - if the limit fails the
        * compressed data will be removed, the prefix will remain.
@@ -335,44 +336,49 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
        * and we have nothing to do - the code will exit through the
        * error case below.
        */
-      else if (expanded_size > 0)
+#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
+    defined(PNG_USER_CHUNK_MALLOC_MAX)
+      else
+#endif
+      if (expanded_size > 0)
       {
          /* Success (maybe) - really uncompress the chunk. */
-	 png_size_t new_size = 0;
-	 png_charp text = png_malloc_warn(png_ptr,
-			prefix_size + expanded_size + 1);
+         png_size_t new_size = 0;
+         png_charp text = png_malloc_warn(png_ptr,
+                        prefix_size + expanded_size + 1);
 
          if (text != NULL)
          {
-	    png_memcpy(text, png_ptr->chunkdata, prefix_size);
-	    new_size = png_inflate(png_ptr,
+            png_memcpy(text, png_ptr->chunkdata, prefix_size);
+            new_size = png_inflate(png_ptr,
                 (png_bytep)(png_ptr->chunkdata + prefix_size),
-		chunklength - prefix_size,
+                chunklength - prefix_size,
                 (png_bytep)(text + prefix_size), expanded_size);
-	    text[prefix_size + expanded_size] = 0; /* just in case */
-
-	    if (new_size == expanded_size)
-	    {
-	       png_free(png_ptr, png_ptr->chunkdata);
-	       png_ptr->chunkdata = text;
-	       *newlength = prefix_size + expanded_size;
-	       return; /* The success return! */
-	    }
+            text[prefix_size + expanded_size] = 0; /* just in case */
+
+            if (new_size == expanded_size)
+            {
+               png_free(png_ptr, png_ptr->chunkdata);
+               png_ptr->chunkdata = text;
+               *newlength = prefix_size + expanded_size;
+               return; /* The success return! */
+            }
       
-	    png_warning(png_ptr, "png_inflate logic error");
-	    png_free(png_ptr, text);
-	 }
-	 else
+            png_warning(png_ptr, "png_inflate logic error");
+            png_free(png_ptr, text);
+         }
+         else
           png_warning(png_ptr, "Not enough memory to decompress chunk");
       }
    }
 
    else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
    {
+#ifdef PNG_STDIO_SUPPORTED
       char umsg[50];
 
-#ifdef PNG_STDIO_SUPPORTED
-      png_snprintf(umsg, sizeof umsg, "Unknown zTXt compression type %d", comp_type);
+      png_snprintf(umsg, sizeof umsg, "Unknown zTXt compression type %d",
+          comp_type);
       png_warning(png_ptr, umsg);
 #else
       png_warning(png_ptr, "Unknown zTXt compression type");
@@ -389,13 +395,13 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
       png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
       if (text != NULL)
       {
-	 if (prefix_size > 0)
+         if (prefix_size > 0)
             png_memcpy(text, png_ptr->chunkdata, prefix_size);
-	 png_free(png_ptr, png_ptr->chunkdata);
-	 png_ptr->chunkdata = text;
+         png_free(png_ptr, png_ptr->chunkdata);
+         png_ptr->chunkdata = text;
 
-	 /* This is an extra zero in the 'uncompressed' part. */
-	 *(png_ptr->chunkdata + prefix_size) = 0x00;
+         /* This is an extra zero in the 'uncompressed' part. */
+         *(png_ptr->chunkdata + prefix_size) = 0x00;
       }
       /* Ignore a malloc error here - it is safe. */
    }
@@ -891,9 +897,11 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
                green_x, green_y, blue_x, blue_y);
 #else
             fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
-               int_x_white, int_y_white, int_x_red, int_y_red);
+               (long)int_x_white, (long)int_y_white,
+               (long)int_x_red, (long)int_y_red);
             fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
-               int_x_green, int_y_green, int_x_blue, int_y_blue);
+               (long)int_x_green, (long)int_y_green,
+               (long)int_x_blue, (long)int_y_blue);
 #endif
 #endif /* PNG_CONSOLE_IO_SUPPORTED */
          }
diff --git a/pngtest.c b/pngtest.c
index a88226d94..84c99f576 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1627,4 +1627,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_4_1 your_png_h_is_not_version_1_4_1;
+typedef version_1_4_2 your_png_h_is_not_version_1_4_2;
diff --git a/pngtrans.c b/pngtrans.c
index 7b217bb3b..f80679a19 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.4.0 [January 3, 2010]
+ * Last changed in libpng 1.4.2 [April 29, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -655,7 +655,6 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
         "This version of libpng does not support user transform info");
 #endif
 }
-#endif
 
 /* This function returns a pointer to the user_transform_ptr associated with
  * the user transform functions.  The application should free any memory
@@ -673,4 +672,6 @@ png_get_user_transform_ptr(png_structp png_ptr)
    return (NULL);
 #endif
 }
+#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
+	  PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/pngwio.c b/pngwio.c
index f4d995b18..513a71a06 100644
--- a/pngwio.c
+++ b/pngwio.c
@@ -155,7 +155,7 @@ png_default_flush(png_structp png_ptr)
  *                 arguments a pointer to a png_struct.  After a call to
  *                 the flush function, there should be no data in any buffers
  *                 or pending transmission.  If the output method doesn't do
- *                 any buffering of ouput, a function prototype must still be
+ *                 any buffering of output, a function prototype must still be
  *                 supplied although it doesn't have to do anything.  If
  *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
  *                 time, output_flush_fn will be ignored, although it must be
diff --git a/trees.c b/trees.c
index 1a6e997ac..56e9bb1c1 100644
--- a/trees.c
+++ b/trees.c
@@ -1,5 +1,5 @@
 /* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2009 Jean-loup Gailly
+ * Copyright (C) 1995-2010 Jean-loup Gailly
  * detect_data_type() function provided freely by Cosmin Truta, 2006
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
@@ -351,13 +351,14 @@ void gen_trees_header()
                 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
     }
 
-    fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
+    fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
     for (i = 0; i < DIST_CODE_LEN; i++) {
         fprintf(header, "%2u%s", _dist_code[i],
                 SEPARATOR(i, DIST_CODE_LEN-1, 20));
     }
 
-    fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
+    fprintf(header,
+        "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
         fprintf(header, "%2u%s", _length_code[i],
                 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
@@ -382,7 +383,7 @@ void gen_trees_header()
 /* ===========================================================================
  * Initialize the tree data structures for a new zlib stream.
  */
-void _tr_init(s)
+void ZLIB_INTERNAL _tr_init(s)
     deflate_state *s;
 {
     tr_static_init();
@@ -867,7 +868,7 @@ local void send_all_trees(s, lcodes, dcodes, blcodes)
 /* ===========================================================================
  * Send a stored block
  */
-void _tr_stored_block(s, buf, stored_len, last)
+void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
     deflate_state *s;
     charf *buf;       /* input block */
     ulg stored_len;   /* length of input block */
@@ -892,7 +893,7 @@ void _tr_stored_block(s, buf, stored_len, last)
  * To simplify the code, we assume the worst case of last real code encoded
  * on one bit only.
  */
-void _tr_align(s)
+void ZLIB_INTERNAL _tr_align(s)
     deflate_state *s;
 {
     send_bits(s, STATIC_TREES<<1, 3);
@@ -921,7 +922,7 @@ void _tr_align(s)
  * Determine the best encoding for the current block: dynamic trees, static
  * trees or store, and output the encoded block to the zip file.
  */
-void _tr_flush_block(s, buf, stored_len, last)
+void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
     deflate_state *s;
     charf *buf;       /* input block, or NULL if too old */
     ulg stored_len;   /* length of input block */
@@ -1022,7 +1023,7 @@ void _tr_flush_block(s, buf, stored_len, last)
  * Save the match info and tally the frequency counts. Return true if
  * the current block must be flushed.
  */
-int _tr_tally (s, dist, lc)
+int ZLIB_INTERNAL _tr_tally (s, dist, lc)
     deflate_state *s;
     unsigned dist;  /* distance of matched string */
     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
diff --git a/trees.h b/trees.h
index 72facf900..d35639d82 100644
--- a/trees.h
+++ b/trees.h
@@ -70,7 +70,7 @@ local const ct_data static_dtree[D_CODES] = {
 {{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
 };
 
-const uch _dist_code[DIST_CODE_LEN] = {
+const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {
  0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
  8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
@@ -99,7 +99,7 @@ const uch _dist_code[DIST_CODE_LEN] = {
 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
 };
 
-const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
+const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {
  0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
diff --git a/zconf.h b/zconf.h
index 4d756e2d9..02ce56c43 100644
--- a/zconf.h
+++ b/zconf.h
@@ -315,10 +315,6 @@
 #  endif
 #endif
 
-#ifdef HAVE_VISIBILITY_PRAGMA
-#  define ZEXTERN __attribute__((visibility ("default"))) extern
-#endif
-
 #ifndef ZEXTERN
 #  define ZEXTERN extern
 #endif
@@ -360,12 +356,25 @@ typedef uLong FAR uLongf;
    typedef Byte       *voidp;
 #endif
 
-#if 1    /* was set to #if 1 by ./configure */
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
 #  define Z_HAVE_UNISTD_H
 #endif
 
-#ifdef Z_HAVE_UNISTD_H
+#ifdef STDC
 #  include <sys/types.h>    /* for off_t */
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
 #  include <unistd.h>       /* for SEEK_* and off_t */
 #  ifdef VMS
 #    include <unixio.h>     /* for off_t */
@@ -375,19 +384,22 @@ typedef uLong FAR uLongf;
 #  endif
 #endif
 
-#ifdef _LARGEFILE64_SOURCE
-#  include <sys/types.h>
-#endif
-
 #ifndef SEEK_SET
 #  define SEEK_SET        0       /* Seek from beginning of file.  */
 #  define SEEK_CUR        1       /* Seek from current position.  */
 #  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
 #endif
+
 #ifndef z_off_t
 #  define z_off_t long
 #endif
 
+#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
+#  define z_off64_t off64_t
+#else
+#  define z_off64_t z_off_t
+#endif
+
 #if defined(__OS400__)
 #  define NO_vsnprintf
 #endif
diff --git a/zlib.h b/zlib.h
index 02fdd64b5..bfbba83e8 100644
--- a/zlib.h
+++ b/zlib.h
@@ -1,5 +1,5 @@
 /* zlib.h -- interface of the 'zlib' general purpose compression library
-  version 1.2.3.9, Mar 11th, 2010
+  version 1.2.5, April 19th, 2010
 
   Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
 
@@ -37,12 +37,12 @@
 extern "C" {
 #endif
 
-#define ZLIB_VERSION "1.2.3.9"
-#define ZLIB_VERNUM 0x1239
+#define ZLIB_VERSION "1.2.5"
+#define ZLIB_VERNUM 0x1250
 #define ZLIB_VER_MAJOR 1
 #define ZLIB_VER_MINOR 2
-#define ZLIB_VER_REVISION 3
-#define ZLIB_VER_SUBREVISION 9
+#define ZLIB_VER_REVISION 5
+#define ZLIB_VER_SUBREVISION 0
 
 /*
     The 'zlib' compression library provides in-memory compression and
@@ -1556,29 +1556,35 @@ ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
         inflateBackInit_((strm), (windowBits), (window), \
                                             ZLIB_VERSION, sizeof(z_stream))
 
-#ifdef _LARGEFILE64_SOURCE
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
-   ZEXTERN off64_t ZEXPORT gzseek64 OF((gzFile, off64_t, int));
-   ZEXTERN off64_t ZEXPORT gztell64 OF((gzFile));
-   ZEXTERN off64_t ZEXPORT gzoffset64 OF((gzFile));
-   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off64_t));
-   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, off64_t));
+   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
 #endif
 
-#if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS == 64
+#if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
 #  define gzopen gzopen64
 #  define gzseek gzseek64
 #  define gztell gztell64
 #  define gzoffset gzoffset64
 #  define adler32_combine adler32_combine64
 #  define crc32_combine crc32_combine64
-#  ifndef _LARGEFILE64_SOURCE
+#  ifdef _LARGEFILE64_SOURCE
      ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
-     ZEXTERN off_t ZEXPORT gzseek64 OF((gzFile, off_t, int));
-     ZEXTERN off_t ZEXPORT gztell64 OF((gzFile));
-     ZEXTERN off_t ZEXPORT gzoffset64 OF((gzFile));
-     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off_t));
-     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, off_t));
+     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
+     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
+     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
+     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
 #  endif
 #else
    ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
@@ -1589,10 +1595,12 @@ ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
    ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
 #endif
 
+/* hack for buggy compilers */
 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
-    struct internal_state {int dummy;}; /* hack for buggy compilers */
+    struct internal_state {int dummy;};
 #endif
 
+/* undocumented functions */
 ZEXTERN const char   * ZEXPORT zError           OF((int));
 ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
 ZEXTERN const uLongf * ZEXPORT get_crc_table    OF((void));
diff --git a/zutil.c b/zutil.c
index 98a55a883..898ed345b 100644
--- a/zutil.c
+++ b/zutil.c
@@ -1,5 +1,5 @@
 /* zutil.c -- target dependent utility functions for the compression library
- * Copyright (C) 1995-2005 Jean-loup Gailly.
+ * Copyright (C) 1995-2005, 2010 Jean-loup Gailly.
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -117,9 +117,9 @@ uLong ZEXPORT zlibCompileFlags()
 #  ifndef verbose
 #    define verbose 0
 #  endif
-int z_verbose = verbose;
+int ZLIB_INTERNAL z_verbose = verbose;
 
-void z_error (m)
+void ZLIB_INTERNAL z_error (m)
     char *m;
 {
     fprintf(stderr, "%s\n", m);
@@ -146,7 +146,7 @@ const char * ZEXPORT zError(err)
 
 #ifndef HAVE_MEMCPY
 
-void zmemcpy(dest, source, len)
+void ZLIB_INTERNAL zmemcpy(dest, source, len)
     Bytef* dest;
     const Bytef* source;
     uInt  len;
@@ -157,7 +157,7 @@ void zmemcpy(dest, source, len)
     } while (--len != 0);
 }
 
-int zmemcmp(s1, s2, len)
+int ZLIB_INTERNAL zmemcmp(s1, s2, len)
     const Bytef* s1;
     const Bytef* s2;
     uInt  len;
@@ -170,7 +170,7 @@ int zmemcmp(s1, s2, len)
     return 0;
 }
 
-void zmemzero(dest, len)
+void ZLIB_INTERNAL zmemzero(dest, len)
     Bytef* dest;
     uInt  len;
 {
@@ -213,7 +213,7 @@ local ptr_table table[MAX_PTR];
  * a protected system like OS/2. Use Microsoft C instead.
  */
 
-voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
 {
     voidpf buf = opaque; /* just to make some compilers happy */
     ulg bsize = (ulg)items*size;
@@ -237,7 +237,7 @@ voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
     return buf;
 }
 
-void  zcfree (voidpf opaque, voidpf ptr)
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 {
     int n;
     if (*(ush*)&ptr != 0) { /* object < 64K */
@@ -272,13 +272,13 @@ void  zcfree (voidpf opaque, voidpf ptr)
 #  define _hfree   hfree
 #endif
 
-voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
 {
     if (opaque) opaque = 0; /* to make compiler happy */
     return _halloc((long)items, size);
 }
 
-void  zcfree (voidpf opaque, voidpf ptr)
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 {
     if (opaque) opaque = 0; /* to make compiler happy */
     _hfree(ptr);
@@ -297,7 +297,7 @@ extern voidp  calloc OF((uInt items, uInt size));
 extern void   free   OF((voidpf ptr));
 #endif
 
-voidpf zcalloc (opaque, items, size)
+voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
     voidpf opaque;
     unsigned items;
     unsigned size;
@@ -307,7 +307,7 @@ voidpf zcalloc (opaque, items, size)
                               (voidpf)calloc(items, size);
 }
 
-void  zcfree (opaque, ptr)
+void ZLIB_INTERNAL zcfree (opaque, ptr)
     voidpf opaque;
     voidpf ptr;
 {
diff --git a/zutil.h b/zutil.h
index 93d655398..258fa8879 100644
--- a/zutil.h
+++ b/zutil.h
@@ -13,30 +13,22 @@
 #ifndef ZUTIL_H
 #define ZUTIL_H
 
-#define ZLIB_INTERNAL
+#if ((__GNUC__-0) * 10 + __GNUC_MINOR__-0 >= 33) && !defined(NO_VIZ)
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
 #include "zlib.h"
 
 #ifdef STDC
-#  if !(defined(_WIN32_WCE) && defined(_MSV_VER))
+#  if !(defined(_WIN32_WCE) && defined(_MSC_VER))
 #    include <stddef.h>
 #  endif
 #  include <string.h>
 #  include <stdlib.h>
 #endif
 
-#if defined(UNDER_CE) && defined(NO_ERRNO_H)
-#  define zseterrno(ERR) SetLastError((DWORD)(ERR))
-#  define zerrno() ((int)GetLastError())
-#else
-#  ifdef NO_ERRNO_H
-     extern int errno;
-#  else
-#    include <errno.h>
-#  endif
-#  define zseterrno(ERR) do { errno = (ERR); } while (0)
-#  define zerrno() errno
-#endif
-
 #ifndef local
 #  define local static
 #endif
@@ -167,10 +159,10 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
   #pragma warn -8066
 #endif
 
-#ifdef _LARGEFILE64_SOURCE
-#  define z_off64_t off64_t
-#else
-#  define z_off64_t z_off_t
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
+    ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+    ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
 #endif
 
         /* common defaults */
@@ -183,12 +175,6 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #  define F_OPEN(name, mode) fopen((name), (mode))
 #endif
 
-#ifdef _LARGEFILE64_SOURCE
-#  define F_OPEN64(name, mode) fopen64((name), (mode))
-#else
-#  define F_OPEN64(name, mode) fopen((name), (mode))
-#endif
-
          /* functions */
 
 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
@@ -250,16 +236,16 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #    define zmemzero(dest, len) memset(dest, 0, len)
 #  endif
 #else
-   extern void zmemcpy  OF((Bytef* dest, const Bytef* source, uInt len));
-   extern int  zmemcmp  OF((const Bytef* s1, const Bytef* s2, uInt len));
-   extern void zmemzero OF((Bytef* dest, uInt len));
+   void ZLIB_INTERNAL zmemcpy OF((Bytef* dest, const Bytef* source, uInt len));
+   int ZLIB_INTERNAL zmemcmp OF((const Bytef* s1, const Bytef* s2, uInt len));
+   void ZLIB_INTERNAL zmemzero OF((Bytef* dest, uInt len));
 #endif
 
 /* Diagnostic functions */
 #ifdef DEBUG
 #  include <stdio.h>
-   extern int z_verbose;
-   extern void z_error    OF((char *m));
+   extern int ZLIB_INTERNAL z_verbose;
+   extern void ZLIB_INTERNAL z_error OF((char *m));
 #  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
 #  define Trace(x) {if (z_verbose>=0) fprintf x ;}
 #  define Tracev(x) {if (z_verbose>0) fprintf x ;}
@@ -276,8 +262,9 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #endif
 
 
-voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
-void   zcfree  OF((voidpf opaque, voidpf ptr));
+voidpf ZLIB_INTERNAL zcalloc OF((voidpf opaque, unsigned items,
+                        unsigned size));
+void ZLIB_INTERNAL zcfree  OF((voidpf opaque, voidpf ptr));
 
 #define ZALLOC(strm, items, size) \
            (*((strm)->zalloc))((strm)->opaque, (items), (size))