[libpng15] Merge with libpng16/pngtest.c, pngvalid.c, gregbook, pngminim

20 files changed, 333 insertions, 285 deletions

diff --git a/ANNOUNCE b/ANNOUNCE
index de1d14fae..ec9290122 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.28beta01 - August 18, 2016
+Libpng 1.5.28beta01 - October 30, 2016
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -26,8 +26,8 @@ Other information:
 
 Changes since the last public release (1.5.27):
 
-version 1.5.28beta01 [August 18, 2016]
-  Merge with current libpng16 pngvalid.c
+version 1.5.28beta01 [October 30, 2016]
+  Merge with current libpng16 gregbook, pngvalid.c, pngtest.c
   Fixed undefined behavior in png_push_save_buffer(). Do not call
     memcpy() with a null source, even if count is zero (Leon Scroggins III).
   Added "Common linking failures" section to INSTALL.
diff --git a/CHANGES b/CHANGES
index d3dec228c..758872674 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4496,8 +4496,8 @@ version 1.5.27rc01 [May 14, 2016]
 version 1.5.27 [May 26, 2016]
   No changes.
 
-version 1.5.28beta01 [August 18, 2016]
-  Merge with current libpng16 pngvalid.c
+version 1.5.28beta01 [October 30, 2016]
+  Merge with current libpng16 gregbook, pngvalid.c, pngtest.c
   Fixed undefined behavior in png_push_save_buffer(). Do not call
     memcpy() with a null source, even if count is zero (Leon Scroggins III).
   Added "Common linking failures" section to INSTALL.
diff --git a/contrib/gregbook/Makefile.unx b/contrib/gregbook/Makefile.unx
index abd8abbaf..b33aae8fc 100644
--- a/contrib/gregbook/Makefile.unx
+++ b/contrib/gregbook/Makefile.unx
@@ -59,15 +59,16 @@ INCS = $(PNGINC) $(ZINC) $(XINC)
 RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
 RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
 WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
-WLIBSs = $(PNGLIBs) $(ZLIBs)
+WLIBSs = $(PNGLIBs) $(ZLIBs) -lm
 
 CC = gcc
 LD = gcc
 RM = rm -f
 CPPFLAGS = $(INCS) -DFEATURE_LOOP
 CFLAGS = -O -Wall
+#CFLAGS = -O -W -Wall -Wextra -pedantic -ansi
 # [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
-# [-ansi, -pedantic and -W can also be used]
+# [-ansi, -pedantic, -Wextra, and -W can also be used]
 LDFLAGS =
 O = .o
 E =
diff --git a/contrib/gregbook/README b/contrib/gregbook/README
index 7b1f6a3ea..fd30f0581 100644
--- a/contrib/gregbook/README
+++ b/contrib/gregbook/README
@@ -15,7 +15,7 @@ of PBMPLUS/NetPBM) and converts them to PNG.
 
 The source code for all three demo programs currently compiles under
 Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
-zinser@decus.de, for making the necessary changes for OpenVMS and for
+zinser at decus.de, for making the necessary changes for OpenVMS and for
 providing an appropriate build script.)  Build instructions can be found
 below.
 
diff --git a/contrib/gregbook/readpng.c b/contrib/gregbook/readpng.c
index f5e1fb1a4..9167403e5 100644
--- a/contrib/gregbook/readpng.c
+++ b/contrib/gregbook/readpng.c
@@ -100,7 +100,8 @@ int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
 
     /* could pass pointers to user-defined error handlers instead of NULLs: */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL, NULL,
+        NULL);
     if (!png_ptr)
         return 4;   /* out of memory */
 
diff --git a/contrib/gregbook/readpng2.c b/contrib/gregbook/readpng2.c
index b9746b756..4d5e38fe2 100644
--- a/contrib/gregbook/readpng2.c
+++ b/contrib/gregbook/readpng2.c
@@ -4,7 +4,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2015 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -51,6 +51,11 @@
       along with this program; if not, write to the Free Software Foundation,
       Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
+  ---------------------------------------------------------------------------
+
+   Changelog:
+     2015-11-12 - Check return value of png_get_bKGD() (Glenn R-P)
+
   ---------------------------------------------------------------------------*/
 
 
@@ -69,6 +74,7 @@ static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
                                  png_uint_32 row_num, int pass);
 static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
 static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg);
 
 
 
@@ -103,8 +109,8 @@ int readpng2_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
-      readpng2_error_handler, NULL);
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), mainprog_ptr,
+      readpng2_error_handler, readpng2_warning_handler);
     if (!png_ptr)
         return 4;   /* out of memory */
 
@@ -136,29 +142,23 @@ int readpng2_init(mainprog_info *mainprog_ptr)
      * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
      * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
     {
-        /* These byte strings were copied from png.h.  If a future libpng
-         * version recognizes more chunks, add them to this list.  If a
-         * future version of readpng2.c recognizes more chunks, delete them
-         * from this list. */
-        static /* const */ png_byte chunks_to_ignore[] = {
-             99,  72,  82,  77, '\0',  /* cHRM */
-            104,  73,  83,  84, '\0',  /* hIST */
-            105,  67,  67,  80, '\0',  /* iCCP */
-            105,  84,  88, 116, '\0',  /* iTXt */
-            111,  70,  70, 115, '\0',  /* oFFs */
-            112,  67,  65,  76, '\0',  /* pCAL */
-            112,  72,  89, 115, '\0',  /* pHYs */
-            115,  66,  73,  84, '\0',  /* sBIT */
-            115,  67,  65,  76, '\0',  /* sCAL */
-            115,  80,  76,  84, '\0',  /* sPLT */
-            115,  84,  69,  82, '\0',  /* sTER */
-            116,  69,  88, 116, '\0',  /* tEXt */
-            116,  73,  77,  69, '\0',  /* tIME */
-            122,  84,  88, 116, '\0'   /* zTXt */
-        };
-
-        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
-          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+        /* These byte strings were copied from png.h.  If a future version
+         * of readpng2.c recognizes more chunks, add them to this list.
+         */
+        static PNG_CONST png_byte chunks_to_process[] = {
+            98,  75,  71,  68, '\0',  /* bKGD */
+           103,  65,  77,  65, '\0',  /* gAMA */
+           115,  82,  71,  66, '\0',  /* sRGB */
+           };
+
+       /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */
+       png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */,
+          NULL, -1);
+
+       /* But do not ignore chunks in the "chunks_to_process" list */
+       png_set_keep_unknown_chunks(png_ptr,
+          0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process,
+          sizeof(chunks_to_process)/5);
     }
 #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
 
@@ -266,36 +266,38 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
     /* since we know we've read all of the PNG file's "header" (i.e., up
      * to IDAT), we can check for a background color here */
 
-    if (mainprog_ptr->need_bgcolor &&
-        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+    if (mainprog_ptr->need_bgcolor)
     {
         png_color_16p pBackground;
 
         /* it is not obvious from the libpng documentation, but this function
          * takes a pointer to a pointer, and it always returns valid red,
          * green and blue values, regardless of color_type: */
-        png_get_bKGD(png_ptr, info_ptr, &pBackground);
-
-        /* however, it always returns the raw bKGD data, regardless of any
-         * bit-depth transformations, so check depth and adjust if necessary */
-        if (bit_depth == 16) {
-            mainprog_ptr->bg_red   = pBackground->red   >> 8;
-            mainprog_ptr->bg_green = pBackground->green >> 8;
-            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
-        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
-            if (bit_depth == 1)
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
-            else if (bit_depth == 2)
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
-            else /* bit_depth == 4 */
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
-        } else {
-            mainprog_ptr->bg_red   = (uch)pBackground->red;
-            mainprog_ptr->bg_green = (uch)pBackground->green;
-            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
+        {
+
+           /* however, it always returns the raw bKGD data, regardless of any
+            * bit-depth transformations, so check depth and adjust if necessary
+            */
+           if (bit_depth == 16) {
+               mainprog_ptr->bg_red   = pBackground->red   >> 8;
+               mainprog_ptr->bg_green = pBackground->green >> 8;
+               mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+           } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+               if (bit_depth == 1)
+                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                     mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+               else if (bit_depth == 2)
+                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                     mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+               else /* bit_depth == 4 */
+                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                     mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+           } else {
+               mainprog_ptr->bg_red   = (uch)pBackground->red;
+               mainprog_ptr->bg_green = (uch)pBackground->green;
+               mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+           }
         }
     }
 
@@ -453,6 +455,8 @@ static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
 
     /* all done */
 
+    (void)info_ptr; /* Unused */
+
     return;
 }
 
@@ -473,7 +477,12 @@ void readpng2_cleanup(mainprog_info *mainprog_ptr)
 }
 
 
-
+static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg)
+{
+    fprintf(stderr, "readpng2 libpng warning: %s\n", msg);
+    fflush(stderr);
+    (void)png_ptr; /* Unused */
+}
 
 
 static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
diff --git a/contrib/gregbook/readppm.c b/contrib/gregbook/readppm.c
index be9a56d95..7fefc3943 100644
--- a/contrib/gregbook/readppm.c
+++ b/contrib/gregbook/readppm.c
@@ -163,8 +163,12 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
 
     /* now we can go ahead and just read the whole image */
 
-    fread(image_data, 1L, rowbytes*height, saved_infile);
-
+    if (fread(image_data, 1L, rowbytes*height, saved_infile) <
+       rowbytes*height) {
+        free (image_data);
+        image_data = NULL;
+        return NULL;
+    }
 
     return image_data;
 }
diff --git a/contrib/gregbook/rpng-win.c b/contrib/gregbook/rpng-win.c
index f53ddc8ec..cd5543937 100644
--- a/contrib/gregbook/rpng-win.c
+++ b/contrib/gregbook/rpng-win.c
@@ -182,7 +182,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
 #ifndef __CYGWIN__
     /* First reenable console output, which normally goes to the bit bucket
      * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
+     * app.  Thanks to David.Geldreich at realviz.com for supplying the magical
      * incantation. */
 
     AllocConsole();
diff --git a/contrib/gregbook/rpng-x.c b/contrib/gregbook/rpng-x.c
index 6d10e1b84..ddd7c58d6 100644
--- a/contrib/gregbook/rpng-x.c
+++ b/contrib/gregbook/rpng-x.c
@@ -26,6 +26,8 @@
     - 1.14:  added support for X resources (thanks to Gerhard Niklasch)
     - 2.00:  dual-licensed (added GNU GPL)
     - 2.01:  fixed improper display of usage screen on PNG error(s)
+    - 2.02:  Added "void(argc);" statement to quiet pedantic compiler warnings
+             about unused variable (GR-P)
 
   ---------------------------------------------------------------------------
 
@@ -80,7 +82,7 @@
 
 #define PROGNAME  "rpng-x"
 #define LONGNAME  "Simple PNG Viewer for X"
-#define VERSION   "2.01 of 16 March 2008"
+#define VERSION   "2.02 of 15 June 2014"
 #define RESNAME   "rpng"        /* our X resource application name */
 #define RESCLASS  "Rpng"        /* our X resource class name */
 
@@ -279,15 +281,17 @@ int main(int argc, char **argv)
           "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
           "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
           "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n",
+          PROGNAME, default_display_exponent);
+
+        fprintf(stderr, "\n"
           "\t\t  to the product of the lookup-table exponent (varies)\n"
           "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
           "    bg  \tdesired background color in 7-character hex RGB format\n"
           "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
           "\t\t  used with transparent images\n"
           "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n"
-          "\n", PROGNAME, default_display_exponent);
+          "is displayed) to quit.\n");
         exit(1);
     }
 
@@ -419,6 +423,8 @@ int main(int argc, char **argv)
 
     rpng_x_cleanup();
 
+    (void)argc; /* Unused */
+
     return 0;
 }
 
diff --git a/contrib/gregbook/rpng2-win.c b/contrib/gregbook/rpng2-win.c
index 223e73740..c924c1c6c 100644
--- a/contrib/gregbook/rpng2-win.c
+++ b/contrib/gregbook/rpng2-win.c
@@ -33,6 +33,8 @@
     - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
               unexpected-EOF and file-read-error cases
     - 2.03:  removed runtime MMX-enabling/disabling and obsolete -mmx* options
+    - 2.04:
+             (GR-P)
 
   ---------------------------------------------------------------------------
 
@@ -299,7 +301,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
 #ifndef __CYGWIN__
     /* Next reenable console output, which normally goes to the bit bucket
      * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
+     * app.  Thanks to David.Geldreich at realviz.com for supplying the magical
      * incantation. */
 
     AllocConsole();
diff --git a/contrib/gregbook/writepng.c b/contrib/gregbook/writepng.c
index 0dda62ea8..c5c953479 100644
--- a/contrib/gregbook/writepng.c
+++ b/contrib/gregbook/writepng.c
@@ -90,7 +90,7 @@ int writepng_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), mainprog_ptr,
       writepng_error_handler, NULL);
     if (!png_ptr)
         return 4;   /* out of memory */
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 13b0b8df2..9b85c3ef3 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1,9 +1,8 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.24 [(PENDING RELEASE)]
- * Copyright (c) 2014-2016 Glenn Randers-Pehrson
- * Written by John Cunningham Bowler
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 2014-2016 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -1115,7 +1114,7 @@ store_warning(png_structp ppIn, png_const_charp message)
    if (!ps->expect_warning)
       store_log(ps, pp, message, 0 /* warning */);
    else
-     ps->saw_warning = 1;
+      ps->saw_warning = 1;
 }
 
 /* These somewhat odd functions are used when reading an image to ensure that
@@ -1242,7 +1241,7 @@ store_image_check(const png_store* ps, png_const_structp pp, int iImage)
 
       image += 2; /* skip image first row markers */
 
-      while (rows-- > 0)
+      for (; rows > 0; --rows)
       {
          if (image[-2] != 190 || image[-1] != 239)
             png_error(pp, "row start overwritten");
@@ -11427,23 +11426,36 @@ perform_interlace_macro_validation(void)
        */
       for (v=0;;)
       {
+         /* The first two tests overflow if the pass row or column is outside
+          * the possible range for a 32-bit result.  In fact the values should
+          * never be outside the range for a 31-bit result, but checking for 32
+          * bits here ensures that if an app uses a bogus pass row or column
+          * (just so long as it fits in a 32 bit integer) it won't get a
+          * possibly dangerous overflow.
+          */
          /* First the base 0 stuff: */
-         m = PNG_ROW_FROM_PASS_ROW(v, pass);
-         f = png_row_from_pass_row(v, pass);
-         if (m != f)
+         if (v < png_pass_rows(0xFFFFFFFFU, pass))
          {
-            fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
-               v, pass, m, f);
-            exit(99);
+            m = PNG_ROW_FROM_PASS_ROW(v, pass);
+            f = png_row_from_pass_row(v, pass);
+            if (m != f)
+            {
+               fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
+                  v, pass, m, f);
+               exit(99);
+            }
          }
 
-         m = PNG_COL_FROM_PASS_COL(v, pass);
-         f = png_col_from_pass_col(v, pass);
-         if (m != f)
+         if (v < png_pass_cols(0xFFFFFFFFU, pass))
          {
-            fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
-               v, pass, m, f);
-            exit(99);
+            m = PNG_COL_FROM_PASS_COL(v, pass);
+            f = png_col_from_pass_col(v, pass);
+            if (m != f)
+            {
+               fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
+                  v, pass, m, f);
+               exit(99);
+            }
          }
 
          m = PNG_ROW_IN_INTERLACE_PASS(v, pass);
diff --git a/contrib/pngminim/README b/contrib/pngminim/README
index 51d5a3c23..e17fe35b6 100644
--- a/contrib/pngminim/README
+++ b/contrib/pngminim/README
@@ -1,3 +1,4 @@
+
 This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa
 to build minimal decoder, encoder, and progressive reader applications.
 
diff --git a/contrib/pngminim/decoder/pngusr.dfa b/contrib/pngminim/decoder/pngusr.dfa
index 70d528bc9..4f402721a 100644
--- a/contrib/pngminim/decoder/pngusr.dfa
+++ b/contrib/pngminim/decoder/pngusr.dfa
@@ -1,6 +1,6 @@
 # pngminim/decoder/pngusr.dfa
 #
-# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -37,3 +37,4 @@ option SETJMP on
 option STDIO on
 option READ_EXPAND on
 option READ_STRIP_16_TO_8 on
+option USER_LIMITS on
diff --git a/contrib/pngminim/decoder/pngusr.h b/contrib/pngminim/decoder/pngusr.h
index 9d9c50c40..cbd7890c7 100644
--- a/contrib/pngminim/decoder/pngusr.h
+++ b/contrib/pngminim/decoder/pngusr.h
@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINRDPNGCONF_H */
diff --git a/contrib/pngminim/encoder/pngusr.dfa b/contrib/pngminim/encoder/pngusr.dfa
index b6cf53daa..1fc24f3f2 100644
--- a/contrib/pngminim/encoder/pngusr.dfa
+++ b/contrib/pngminim/encoder/pngusr.dfa
@@ -13,7 +13,8 @@ everything = off
 # Switch on the write code - this makes a minimalist encoder
 
 option WRITE on
-# These 2 options are required if you need to read PGM (P1 or P4) PGM files.
+
+# These 2 options are required if you need to read PBM (P1 or P4) files.
 option WRITE_INVERT on
 option WRITE_PACK on
 
diff --git a/contrib/pngminim/encoder/pngusr.h b/contrib/pngminim/encoder/pngusr.h
index 2033aadb2..997d44fe9 100644
--- a/contrib/pngminim/encoder/pngusr.h
+++ b/contrib/pngminim/encoder/pngusr.h
@@ -1,6 +1,6 @@
 /* minwrpngconf.h: headers to make a minimal png-write-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINWRPNGCONF_H */
diff --git a/contrib/pngminim/preader/pngusr.dfa b/contrib/pngminim/preader/pngusr.dfa
index 216c421ca..ac297f41b 100644
--- a/contrib/pngminim/preader/pngusr.dfa
+++ b/contrib/pngminim/preader/pngusr.dfa
@@ -1,6 +1,6 @@
 # pngminim/preader/pngusr.dfa
 #
-# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
diff --git a/contrib/pngminim/preader/pngusr.h b/contrib/pngminim/preader/pngusr.h
index 73cfecfbf..80db3bb17 100644
--- a/contrib/pngminim/preader/pngusr.h
+++ b/contrib/pngminim/preader/pngusr.h
@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2009, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2009, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINPRDPNGCONF_H */
diff --git a/pngtest.c b/pngtest.c
index 4ee374688..57f141e9e 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,8 +1,8 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.25 [December 3, 2015]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
  *
@@ -130,13 +130,13 @@ static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
 static int
 tIME_to_str(png_structp png_ptr, png_charp ts, png_const_timep t)
 {
-    png_const_charp str = png_convert_to_rfc1123(png_ptr, t);
+   png_const_charp str = png_convert_to_rfc1123(png_ptr, t);
 
-    if (str == NULL)
-        return 0;
+   if (str == NULL)
+       return 0;
 
-    strcpy(ts, str);
-    return 1;
+   strcpy(ts, str);
+   return 1;
 }
 #endif /* older libpng */
 #endif
@@ -240,95 +240,95 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
     *  png_byte pixel_depth   bits per pixel (depth*channels)
     */
 
-    /* Counts the number of zero samples (or zero pixels if color_type is 3 */
+   /* Counts the number of zero samples (or zero pixels if color_type is 3 */
 
-    if (row_info->color_type == 0 || row_info->color_type == 3)
-    {
-       int pos = 0;
-       png_uint_32 n, nstop;
+   if (row_info->color_type == 0 || row_info->color_type == 3)
+   {
+      int pos = 0;
+      png_uint_32 n, nstop;
 
-       for (n = 0, nstop=row_info->width; n<nstop; n++)
-       {
-          if (row_info->bit_depth == 1)
-          {
-             if (((*dp << pos++ ) & 0x80) == 0)
-                zero_samples++;
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         if (row_info->bit_depth == 1)
+         {
+            if (((*dp << pos++ ) & 0x80) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 2)
-          {
-             if (((*dp << (pos+=2)) & 0xc0) == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 2)
+         {
+            if (((*dp << (pos+=2)) & 0xc0) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 4)
-          {
-             if (((*dp << (pos+=4)) & 0xf0) == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 4)
+         {
+            if (((*dp << (pos+=4)) & 0xf0) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 8)
-             if (*dp++ == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 8)
+            if (*dp++ == 0)
+               zero_samples++;
 
-          if (row_info->bit_depth == 16)
-          {
-             if ((*dp | *(dp+1)) == 0)
-                zero_samples++;
-             dp+=2;
-          }
-       }
-    }
-    else /* Other color types */
-    {
-       png_uint_32 n, nstop;
-       int channel;
-       int color_channels = row_info->channels;
-       if (row_info->color_type > 3)
-          color_channels--;
-
-       for (n = 0, nstop=row_info->width; n<nstop; n++)
-       {
-          for (channel = 0; channel < color_channels; channel++)
-          {
-             if (row_info->bit_depth == 8)
-                if (*dp++ == 0)
-                   zero_samples++;
+         if (row_info->bit_depth == 16)
+         {
+            if ((*dp | *(dp+1)) == 0)
+               zero_samples++;
+            dp+=2;
+         }
+      }
+   }
+   else /* Other color types */
+   {
+      png_uint_32 n, nstop;
+      int channel;
+      int color_channels = row_info->channels;
+      if (row_info->color_type > 3)
+         color_channels--;
 
-             if (row_info->bit_depth == 16)
-             {
-                if ((*dp | *(dp+1)) == 0)
-                   zero_samples++;
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         for (channel = 0; channel < color_channels; channel++)
+         {
+            if (row_info->bit_depth == 8)
+               if (*dp++ == 0)
+                  zero_samples++;
 
-                dp+=2;
-             }
-          }
-          if (row_info->color_type > 3)
-          {
-             dp++;
-             if (row_info->bit_depth == 16)
-                dp++;
-          }
-       }
-    }
+            if (row_info->bit_depth == 16)
+            {
+               if ((*dp | *(dp+1)) == 0)
+                  zero_samples++;
+
+               dp+=2;
+            }
+         }
+         if (row_info->color_type > 3)
+         {
+            dp++;
+            if (row_info->bit_depth == 16)
+               dp++;
+         }
+      }
+   }
 }
 #endif /* WRITE_USER_TRANSFORM */
 
@@ -345,10 +345,10 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 #ifdef PNG_IO_STATE_SUPPORTED
 void
 pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
-   png_uint_32 io_op);
+    png_uint_32 io_op);
 void
 pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
-   png_uint_32 io_op)
+    png_uint_32 io_op)
 {
    png_uint_32 io_state = png_get_io_state(png_ptr);
    int err = 0;
@@ -532,7 +532,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
       memory_infop pinfo;
       png_set_mem_fn(png_ptr, NULL, NULL, NULL);
       pinfo = (memory_infop)png_malloc(png_ptr,
-         (sizeof *pinfo));
+          (sizeof *pinfo));
       pinfo->size = size;
       current_allocation += size;
       total_allocation += size;
@@ -562,7 +562,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
 
       if (verbose != 0)
          printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
-            pinfo->pointer);
+             pinfo->pointer);
 
       return (png_voidp)(pinfo->pointer);
    }
@@ -769,9 +769,9 @@ write_vpAg_chunk(png_structp write_ptr)
 
    if (verbose != 0)
       fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
-        (unsigned long)user_chunk_data.vpAg_width,
-        (unsigned long)user_chunk_data.vpAg_height,
-        user_chunk_data.vpAg_units);
+          (unsigned long)user_chunk_data.vpAg_width,
+          (unsigned long)user_chunk_data.vpAg_height,
+          user_chunk_data.vpAg_units);
 
    png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width);
    png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height);
@@ -812,7 +812,7 @@ write_chunks(png_structp write_ptr, int location)
 #ifdef PNG_TEXT_SUPPORTED
 static void
 pngtest_check_text_support(png_structp png_ptr, png_textp text_ptr,
-   int num_text)
+    int num_text)
 {
    while (num_text > 0)
    {
@@ -894,26 +894,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    pngtest_debug("Allocating read and write structures");
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    read_ptr =
-      png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
-      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+       png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    read_ptr =
-      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+       png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
-      pngtest_warning);
+       pngtest_warning);
 
 #ifdef PNG_WRITE_SUPPORTED
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    write_ptr =
-      png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
-      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+       png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    write_ptr =
-      png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+       png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
-      pngtest_warning);
+       pngtest_warning);
 #endif
    pngtest_debug("Allocating read_info, write_info and end_info structures");
    read_info_ptr = png_create_info_struct(read_ptr);
@@ -926,7 +926,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
    init_callback_info(read_info_ptr);
    png_set_read_user_chunk_fn(read_ptr, &user_chunk_data,
-     read_user_chunk_callback);
+       read_user_chunk_callback);
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
@@ -964,15 +964,16 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #endif
 #endif
 
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
    if (strict != 0)
    {
       /* Treat png_benign_error() as errors on read */
       png_set_benign_errors(read_ptr, 0);
 
-#ifdef PNG_WRITE_SUPPORTED
+# ifdef PNG_WRITE_SUPPORTED
       /* Treat them as errors on write */
       png_set_benign_errors(write_ptr, 0);
-#endif
+# endif
 
       /* if strict is not set, then app warnings and errors are treated as
        * warnings in release builds, but not in unstable builds; this can be
@@ -985,10 +986,15 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       /* Allow application (pngtest) errors and warnings to pass */
       png_set_benign_errors(read_ptr, 1);
 
-#ifdef PNG_WRITE_SUPPORTED
+      /* Turn off CRC and ADLER32 checking while reading */
+      png_set_crc_action(read_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+
+# ifdef PNG_WRITE_SUPPORTED
       png_set_benign_errors(write_ptr, 1);
-#endif
+# endif
+
    }
+#endif /* BENIGN_ERRORS */
 
    pngtest_debug("Initializing input and output streams");
 #ifdef PNG_STDIO_SUPPORTED
@@ -1001,9 +1007,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  ifdef PNG_WRITE_SUPPORTED
    png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
 #    ifdef PNG_WRITE_FLUSH_SUPPORTED
-      pngtest_flush);
+       pngtest_flush);
 #    else
-      NULL);
+       NULL);
 #    endif
 #  endif
 #endif
@@ -1043,11 +1049,11 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
     */
 #ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
-      NULL, 0);
+       NULL, 0);
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
-      NULL, 0);
+       NULL, 0);
 #endif
 #endif
 
@@ -1071,7 +1077,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
           &color_type, &interlace_type, &compression_type, &filter_type) != 0)
       {
          png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
-            color_type, interlace_type, compression_type, filter_type);
+             color_type, interlace_type, compression_type, filter_type);
          /* num_passes may not be available below if interlace support is not
           * provided by libpng for both read and write.
           */
@@ -1098,13 +1104,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_cHRM_SUPPORTED
    {
       png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
-         blue_y;
+          blue_y;
 
       if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
-         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+          &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
-            red_y, green_x, green_y, blue_x, blue_y);
+             red_y, green_x, green_y, blue_x, blue_y);
       }
    }
 #endif
@@ -1121,13 +1127,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_cHRM_SUPPORTED
    {
       double white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
-         blue_y;
+          blue_y;
 
       if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
-         &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+          &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
-            red_y, green_x, green_y, blue_x, blue_y);
+             red_y, green_x, green_y, blue_x, blue_y);
       }
    }
 #endif
@@ -1149,10 +1155,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int compression_type;
 
       if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
-                      &profile, &proflen) != 0)
+          &profile, &proflen) != 0)
       {
          png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
-                      profile, proflen);
+             profile, proflen);
       }
    }
 #endif
@@ -1209,10 +1215,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int type, nparams;
 
       if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
-         &nparams, &units, &params) != 0)
+          &nparams, &units, &params) != 0)
       {
          png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
-            nparams, units, params);
+             nparams, units, params);
       }
    }
 #endif
@@ -1242,7 +1248,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       double scal_width, scal_height;
 
       if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
-         &scal_height) != 0)
+          &scal_height) != 0)
       {
          png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
       }
@@ -1254,7 +1260,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_charp scal_width, scal_height;
 
       if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
-          &scal_height) != 0)
+           &scal_height) != 0)
       {
          png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
              scal_height);
@@ -1295,7 +1301,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             for (i=0; i<num_text; i++)
             {
                printf("   Text compression[%d]=%d\n",
-                     i, text_ptr[i].compression);
+                   i, text_ptr[i].compression);
             }
          }
 
@@ -1332,7 +1338,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_color_16p trans_color;
 
       if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
-         &trans_color) != 0)
+          &trans_color) != 0)
       {
          int sample_max = (1 << bit_depth);
          /* libpng doesn't reject a tRNS chunk with out-of-range samples */
@@ -1351,12 +1357,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_unknown_chunkp unknowns;
       int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
-         &unknowns);
+          &unknowns);
 
       if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
-           num_unknowns);
+             num_unknowns);
 #if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
           * generated locations in write_end_info_ptr are wrong prior to 1.6.0
@@ -1366,7 +1372,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             int i;
             for (i = 0; i < num_unknowns; i++)
               png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
-                unknowns[i].location);
+                  unknowns[i].location);
          }
 #endif
       }
@@ -1386,12 +1392,17 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_write_info(write_ptr, write_info_ptr);
 
    write_chunks(write_ptr, before_IDAT); /* after PLTE */
+
+#ifdef PNG_COMPRESSION_COMPAT
+   /* Test the 'compatibility' setting here, if it is available. */
+   png_set_compression(write_ptr, PNG_COMPRESSION_COMPAT);
+#endif
 #endif
 
 #ifdef SINGLE_ROWBUF_ALLOC
    pngtest_debug("Allocating row buffer...");
    row_buf = (png_bytep)png_malloc(read_ptr,
-      png_get_rowbytes(read_ptr, read_info_ptr));
+       png_get_rowbytes(read_ptr, read_info_ptr));
 
    pngtest_debug1("\t0x%08lx", (unsigned long)row_buf);
 #endif /* SINGLE_ROWBUF_ALLOC */
@@ -1405,10 +1416,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
     */
    if (png_set_interlace_handling(read_ptr) != num_passes)
       png_error(write_ptr,
-            "png_set_interlace_handling(read): wrong pass count ");
+          "png_set_interlace_handling(read): wrong pass count ");
    if (png_set_interlace_handling(write_ptr) != num_passes)
       png_error(write_ptr,
-            "png_set_interlace_handling(write): wrong pass count ");
+          "png_set_interlace_handling(write): wrong pass count ");
 #else /* png_set_interlace_handling not called on either read or write */
 #  define calc_pass_height
 #endif /* not using libpng interlace handling */
@@ -1445,10 +1456,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
 
          row_buf = (png_bytep)png_malloc(read_ptr,
-            png_get_rowbytes(read_ptr, read_info_ptr));
+             png_get_rowbytes(read_ptr, read_info_ptr));
 
          pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf,
-            (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
+             (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
 
 #endif /* !SINGLE_ROWBUF_ALLOC */
          png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
@@ -1506,7 +1517,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             for (i=0; i<num_text; i++)
             {
                printf("   Text compression[%d]=%d\n",
-                     i, text_ptr[i].compression);
+                   i, text_ptr[i].compression);
             }
          }
 
@@ -1540,12 +1551,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_unknown_chunkp unknowns;
       int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
-         &unknowns);
+          &unknowns);
 
       if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
-           num_unknowns);
+             num_unknowns);
 #if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
           * generated locations in write_end_info_ptr are wrong prior to 1.6.0
@@ -1555,7 +1566,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             int i;
             for (i = 0; i < num_unknowns; i++)
               png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
-                unknowns[i].location);
+                  unknowns[i].location);
          }
 #endif
       }
@@ -1589,7 +1600,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       iwidth = png_get_image_width(write_ptr, write_info_ptr);
       iheight = png_get_image_height(write_ptr, write_info_ptr);
       fprintf(STDERR, "\n Image width = %lu, height = %lu\n",
-         (unsigned long)iwidth, (unsigned long)iheight);
+          (unsigned long)iwidth, (unsigned long)iheight);
    }
 #endif
 
@@ -1622,7 +1633,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
        * above, but this is safe.
        */
       fprintf(STDERR, "\n  %s: %d libpng errors found (%d warnings)",
-         inname, error_count, warning_count);
+          inname, error_count, warning_count);
 
       if (strict != 0)
          return (1);
@@ -1633,14 +1644,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       else if (unsupported_chunks > 0)
       {
          fprintf(STDERR, "\n  %s: unsupported chunks (%d)%s",
-            inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
+             inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
       }
 #  endif
 
    else if (warning_count > 0)
    {
       fprintf(STDERR, "\n  %s: %d libpng warnings found",
-         inname, warning_count);
+          inname, warning_count);
 
       if (strict != 0)
          return (1);
@@ -1676,18 +1687,19 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          if (num_in != num_out)
          {
             fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
-                    inname, outname);
+                inname, outname);
 
             if (wrote_question == 0 && unsupported_chunks == 0)
             {
                fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
-                 inname, PNG_ZBUF_SIZE);
+                   "   Was %s written with the same maximum IDAT"
+                   " chunk size (%d bytes),",
+                   inname, PNG_ZBUF_SIZE);
                fprintf(STDERR,
-                 "\n   filtering heuristic (libpng default), compression");
+                   "\n   filtering heuristic (libpng default), compression");
                fprintf(STDERR,
-                 " level (zlib default),\n   and zlib version (%s)?\n\n",
-                 ZLIB_VERSION);
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
+                   ZLIB_VERSION);
                wrote_question = 1;
             }
 
@@ -1707,17 +1719,18 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          if (memcmp(inbuf, outbuf, num_in))
          {
             fprintf(STDERR, "\nFiles %s and %s are different\n", inname,
-               outname);
+                outname);
 
             if (wrote_question == 0 && unsupported_chunks == 0)
             {
                fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                   "   Was %s written with the same maximum"
+                   " IDAT chunk size (%d bytes),",
                     inname, PNG_ZBUF_SIZE);
                fprintf(STDERR,
-                 "\n   filtering heuristic (libpng default), compression");
+                   "\n   filtering heuristic (libpng default), compression");
                fprintf(STDERR,
-                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
                  ZLIB_VERSION);
                wrote_question = 1;
             }
@@ -1768,12 +1781,12 @@ main(int argc, char *argv[])
    fprintf(STDERR, "%s", png_get_copyright(NULL));
    /* Show the version of libpng used in building the library */
    fprintf(STDERR, " library (%lu):%s",
-      (unsigned long)png_access_version_number(),
-      png_get_header_version(NULL));
+       (unsigned long)png_access_version_number(),
+       png_get_header_version(NULL));
 
    /* Show the version of libpng used in building the application */
    fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER,
-      PNG_HEADER_VERSION_STRING);
+       PNG_HEADER_VERSION_STRING);
 
    /* Do some consistency checking on the memory allocation settings, I'm
     * not sure this matters, but it is nice to know, the first of these
@@ -1791,7 +1804,7 @@ main(int argc, char *argv[])
    if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING))
    {
       fprintf(STDERR,
-         "Warning: versions are different between png.h and png.c\n");
+          "Warning: versions are different between png.h and png.c\n");
       fprintf(STDERR, "  png.h version: %s\n", PNG_LIBPNG_VER_STRING);
       fprintf(STDERR, "  png.c version: %s\n\n", png_libpng_ver);
       ++ierror;
@@ -1846,19 +1859,19 @@ main(int argc, char *argv[])
    }
 
    if (multiple == 0 && argc == 3 + verbose)
-     outname = argv[2 + verbose];
+      outname = argv[2 + verbose];
 
    if ((multiple == 0 && argc > 3 + verbose) ||
        (multiple != 0 && argc < 2))
    {
-     fprintf(STDERR,
-       "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
-        argv[0], argv[0]);
-     fprintf(STDERR,
-       "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
-     fprintf(STDERR,
-       "  with -m %s is used as a temporary file\n", outname);
-     exit(1);
+      fprintf(STDERR,
+          "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
+          argv[0], argv[0]);
+      fprintf(STDERR,
+          "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
+      fprintf(STDERR,
+          "  with -m %s is used as a temporary file\n", outname);
+      exit(1);
    }
 
    if (multiple != 0)
@@ -1879,7 +1892,7 @@ main(int argc, char *argv[])
          {
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
             fprintf(STDERR, "\n PASS (%lu zero samples)\n",
-               (unsigned long)zero_samples);
+                (unsigned long)zero_samples);
 #else
             fprintf(STDERR, " PASS\n");
 #endif
@@ -1899,20 +1912,20 @@ main(int argc, char *argv[])
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          if (allocation_now != current_allocation)
             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
-               current_allocation - allocation_now);
+                current_allocation - allocation_now);
 
          if (current_allocation != 0)
          {
             memory_infop pinfo = pinformation;
 
             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
-               current_allocation);
+                current_allocation);
 
             while (pinfo != NULL)
             {
                fprintf(STDERR, " %lu bytes at %p\n",
-                 (unsigned long)pinfo->size,
-                 pinfo->pointer);
+                   (unsigned long)pinfo->size,
+                   pinfo->pointer);
                pinfo = pinfo->next;
             }
          }
@@ -1920,13 +1933,13 @@ main(int argc, char *argv[])
       }
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          fprintf(STDERR, " Current memory allocation: %10d bytes\n",
-            current_allocation);
+             current_allocation);
          fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
-            maximum_allocation);
+             maximum_allocation);
          fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
-            total_allocation);
+             total_allocation);
          fprintf(STDERR, "     Number of allocations: %10d\n",
-            num_allocations);
+             num_allocations);
 #endif
    }
 
@@ -1961,7 +1974,7 @@ main(int argc, char *argv[])
             {
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
                 fprintf(STDERR, "\n PASS (%lu zero samples)\n",
-                   (unsigned long)zero_samples);
+                    (unsigned long)zero_samples);
 #else
                 fprintf(STDERR, " PASS\n");
 #endif
@@ -1988,19 +2001,19 @@ main(int argc, char *argv[])
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          if (allocation_now != current_allocation)
              fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
-               current_allocation - allocation_now);
+                 current_allocation - allocation_now);
 
          if (current_allocation != 0)
          {
              memory_infop pinfo = pinformation;
 
              fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
-                current_allocation);
+                 current_allocation);
 
              while (pinfo != NULL)
              {
                 fprintf(STDERR, " %lu bytes at %p\n",
-                   (unsigned long)pinfo->size, pinfo->pointer);
+                    (unsigned long)pinfo->size, pinfo->pointer);
                 pinfo = pinfo->next;
              }
           }
@@ -2008,13 +2021,13 @@ main(int argc, char *argv[])
        }
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
        fprintf(STDERR, " Current memory allocation: %10d bytes\n",
-          current_allocation);
+           current_allocation);
        fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
-          maximum_allocation);
+           maximum_allocation);
        fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
-          total_allocation);
+           total_allocation);
        fprintf(STDERR, "     Number of allocations: %10d\n",
-            num_allocations);
+           num_allocations);
 #endif
    }
 
@@ -2023,13 +2036,13 @@ main(int argc, char *argv[])
    t_misc += (t_stop - t_start);
    t_start = t_stop;
    fprintf(STDERR, " CPU time used = %.3f seconds",
-      (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
+       (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, " (decoding %.3f,\n",
-      t_decode/(float)CLOCKS_PER_SEC);
+       t_decode/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, "        encoding %.3f ,",
-      t_encode/(float)CLOCKS_PER_SEC);
+       t_encode/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, " other %.3f seconds)\n\n",
-      t_misc/(float)CLOCKS_PER_SEC);
+       t_misc/(float)CLOCKS_PER_SEC);
 #endif
 
    if (ierror == 0)
@@ -2041,19 +2054,19 @@ main(int argc, char *argv[])
    dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    fprintf(STDERR, " Default limits:\n");
    fprintf(STDERR, "  width_max  = %lu\n",
-      (unsigned long) png_get_user_width_max(dummy_ptr));
+       (unsigned long) png_get_user_width_max(dummy_ptr));
    fprintf(STDERR, "  height_max = %lu\n",
-      (unsigned long) png_get_user_height_max(dummy_ptr));
+       (unsigned long) png_get_user_height_max(dummy_ptr));
    if (png_get_chunk_cache_max(dummy_ptr) == 0)
       fprintf(STDERR, "  cache_max  = unlimited\n");
    else
       fprintf(STDERR, "  cache_max  = %lu\n",
-         (unsigned long) png_get_chunk_cache_max(dummy_ptr));
+          (unsigned long) png_get_chunk_cache_max(dummy_ptr));
    if (png_get_chunk_malloc_max(dummy_ptr) == 0)
       fprintf(STDERR, "  malloc_max = unlimited\n");
    else
       fprintf(STDERR, "  malloc_max = %lu\n",
-         (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
+          (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
    png_destroy_read_struct(&dummy_ptr, NULL, NULL);
 
    return (int)(ierror != 0);
@@ -2063,7 +2076,7 @@ int
 main(void)
 {
    fprintf(STDERR,
-      " test ignored because libpng was not built with read support\n");
+       " test ignored because libpng was not built with read support\n");
    /* And skip this test */
    return PNG_LIBPNG_VER < 10600 ? 0 : 77;
 }