Assume POSIX 1003.1-1988 or later for errno.h.

* lib-src/movemail.c (main): Assume EAGAIN and EBUSY.
* src/dired.c (directory_files_internal, file_name_completion):
Assume EAGAIN and EINTR are defined.
* src/fileio.c (Fcopy_file): Assume EISDIR is defined.
* src/gmalloc.c (ENOMEM, EINVAL): Assume they're defined.
* src/gnutls.c (emacs_gnutls_write): Assume EAGAIN is defined.
* src/lread.c (readbyte_from_file): Assume EINTR is defined.
* src/process.c (wait_reading_process_output, send_process) [subprocesses]:
Assume EIO and EAGAIN are defined.
* src/unexcoff.c (write_segment): Assume EFAULT is defined.

Fixes: debbugs:12968

9 files changed, 36 insertions, 69 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d841812bceb..0594f73540b 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2012-11-27  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Assume POSIX 1003.1-1988 or later for errno.h (Bug#12968).
+	* dired.c (directory_files_internal, file_name_completion):
+	Assume EAGAIN and EINTR are defined.
+	* fileio.c (Fcopy_file): Assume EISDIR is defined.
+	* gmalloc.c (ENOMEM, EINVAL): Assume they're defined.
+	* gnutls.c (emacs_gnutls_write): Assume EAGAIN is defined.
+	* lread.c (readbyte_from_file): Assume EINTR is defined.
+	* process.c (wait_reading_process_output, send_process) [subprocesses]:
+	Assume EIO and EAGAIN are defined.
+	* unexcoff.c (write_segment): Assume EFAULT is defined.
+
 2012-11-27  Eli Zaretskii  <eliz@gnu.org>
 
 	* fontset.c (Finternal_char_font): Return nil on non-GUI frames.
diff --git a/src/dired.c b/src/dired.c
index 3530b74ecb4..54bdc083f70 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -193,19 +193,15 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
 
       errno = 0;
       dp = readdir (d);
-
-      if (dp == NULL && (0
-#ifdef EAGAIN
-			 || errno == EAGAIN
-#endif
-#ifdef EINTR
-			 || errno == EINTR
-#endif
-			 ))
-	{ QUIT; continue; }
-
-      if (dp == NULL)
-	break;
+      if (!dp)
+	{
+	  if (errno == EAGAIN || errno == EINTR)
+	    {
+	      QUIT;
+	      continue;
+	    }
+	  break;
+	}
 
       len = dirent_namelen (dp);
       name = finalname = make_unibyte_string (dp->d_name, len);
@@ -480,17 +476,15 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
 
       errno = 0;
       dp = readdir (d);
-      if (dp == NULL && (0
-# ifdef EAGAIN
-			 || errno == EAGAIN
-# endif
-# ifdef EINTR
-			 || errno == EINTR
-# endif
-			 ))
-	{ QUIT; continue; }
-
-      if (!dp) break;
+      if (!dp)
+	{
+	  if (errno == EAGAIN || errno == EINTR)
+	    {
+	      QUIT;
+	      continue;
+	    }
+	  break;
+	}
 
       len = dirent_namelen (dp);
 
diff --git a/src/fileio.c b/src/fileio.c
index 442c66550d3..98b27035597 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1995,10 +1995,8 @@ on the system, we copy the SELinux context of FILE to NEWNAME.  */)
     {
       if (!(S_ISREG (st.st_mode)) && !(S_ISLNK (st.st_mode)))
 	{
-#if defined (EISDIR)
 	  /* Get a better looking error message. */
 	  errno = EISDIR;
-#endif /* EISDIR */
 	  report_file_error ("Non-regular file", Fcons (file, Qnil));
 	}
     }
diff --git a/src/gmalloc.c b/src/gmalloc.c
index dc584955661..c325ca79910 100644
--- a/src/gmalloc.c
+++ b/src/gmalloc.c
@@ -1645,14 +1645,6 @@ memalign (size_t alignment, size_t size)
   return result;
 }
 
-#ifndef ENOMEM
-#define ENOMEM 12
-#endif
-
-#ifndef EINVAL
-#define EINVAL 22
-#endif
-
 int
 posix_memalign (void **memptr, size_t alignment, size_t size)
 {
diff --git a/src/gnutls.c b/src/gnutls.c
index e3d84a0b61b..03f753fa8cc 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -359,12 +359,7 @@ emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, ptrdiff_t nbyte)
 
   if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
     {
-#ifdef EWOULDBLOCK
-      errno = EWOULDBLOCK;
-#endif
-#ifdef EAGAIN
       errno = EAGAIN;
-#endif
       return 0;
     }
 
@@ -384,14 +379,7 @@ emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, ptrdiff_t nbyte)
 		 appropriately so that send_process retries the
 		 correct way instead of erroring out. */
 	      if (rtnval == GNUTLS_E_AGAIN)
-		{
-#ifdef EWOULDBLOCK
-		  errno = EWOULDBLOCK;
-#endif
-#ifdef EAGAIN
-		  errno = EAGAIN;
-#endif
-		}
+		errno = EAGAIN;
 	      break;
 	    }
 	}
diff --git a/src/keyboard.c b/src/keyboard.c
index 0ad6d18c044..60e6d71cdff 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -6960,10 +6960,7 @@ tty_read_avail_input (struct terminal *terminal,
             an EAGAIN error.  Does anybody know of a situation
             where a retry is actually needed?  */
 #if 0
-         nread < 0 && (errno == EAGAIN
-#ifdef EFAULT
-                       || errno == EFAULT
-#endif
+         nread < 0 && (errno == EAGAIN || errno == EFAULT
 #ifdef EBADSLT
                        || errno == EBADSLT
 #endif
diff --git a/src/lread.c b/src/lread.c
index 6d0ff9f780e..6647382a254 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -440,7 +440,6 @@ readbyte_from_file (int c, Lisp_Object readcharfun)
   block_input ();
   c = getc (instream);
 
-#ifdef EINTR
   /* Interrupted reads have been observed while reading over the network.  */
   while (c == EOF && ferror (instream) && errno == EINTR)
     {
@@ -450,7 +449,6 @@ readbyte_from_file (int c, Lisp_Object readcharfun)
       clearerr (instream);
       c = getc (instream);
     }
-#endif
 
   unblock_input ();
 
diff --git a/src/process.c b/src/process.c
index 0036ce595f5..b23f06fd025 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4432,14 +4432,8 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 		  total_nread += nread;
 		  got_some_input = 1;
 		}
-#ifdef EIO
-	      else if (nread == -1 && EIO == errno)
+	      else if (nread == -1 && (errno == EIO || errno == EAGAIN))
 		break;
-#endif
-#ifdef EAGAIN
-	      else if (nread == -1 && EAGAIN == errno)
-		break;
-#endif
 #ifdef EWOULDBLOCK
 	      else if (nread == -1 && EWOULDBLOCK == errno)
 		break;
@@ -5517,13 +5511,10 @@ send_process (Lisp_Object proc, const char *buf, ptrdiff_t len,
 
 	  if (rv < 0)
 	    {
-	      if (0
+	      if (errno == EAGAIN
 #ifdef EWOULDBLOCK
 		  || errno == EWOULDBLOCK
 #endif
-#ifdef EAGAIN
-		  || errno == EAGAIN
-#endif
 		  )
 		/* Buffer is full.  Wait, accepting input;
 		   that may allow the program
diff --git a/src/unexcoff.c b/src/unexcoff.c
index 966dd58cb6e..6e29951a962 100644
--- a/src/unexcoff.c
+++ b/src/unexcoff.c
@@ -332,11 +332,7 @@ write_segment (int new, const char *ptr, const char *end)
 	 a gap between the old text segment and the old data segment.
 	 This gap has probably been remapped into part of the text segment.
 	 So write zeros for it.  */
-      if (ret == -1
-#ifdef EFAULT
-	  && errno == EFAULT
-#endif
-	  )
+      if (ret == -1 && errno == EFAULT)
 	{
 	  /* Write only a page of zeros at once,
 	     so that we don't overshoot the start