bug#12968: Assume POSIX 1003.1-1988 or later for errno.h.

[Paul Eggert]

Here's a patch to simplify Emacs by assuming
POSIX 1003.1-1988 or later for errno.h, which I plan
to install soon.  This should be safe as other parts of Emacs
are already assuming the relevant macros.  I haven't tested
this on Microsoft platforms though.

=== modified file 'lib-src/ChangeLog'
--- lib-src/ChangeLog   2012-11-23 08:28:06 +0000
+++ lib-src/ChangeLog   2012-11-23 08:56:17 +0000
@@ -1,5 +1,8 @@
 2012-11-23  Paul Eggert  <eggert@cs.ucla.edu>
 
+       Assume POSIX 1003.1-1988 or later for errno.h.
+       * movemail.c (main): Assume EAGAIN and EBUSY.
+
        movemail: treat EACCES etc. failures as permanent
        * movemail.c (main): Treat any link failure other than EEXIST as a
        permanent failure, not just EPERM.  EACCES, for example.

=== modified file 'lib-src/movemail.c'
--- lib-src/movemail.c  2012-11-23 08:28:06 +0000
+++ lib-src/movemail.c  2012-11-23 08:56:17 +0000
@@ -430,22 +430,10 @@
         for certain failure codes.  */
       if (status < 0)
        {
-         if (++lockcount <= 5)
+         if (++lockcount <= 5 && (errno == EAGAIN || errno == EBUSY))
            {
-#ifdef EAGAIN
-             if (errno == EAGAIN)
-               {
-                 sleep (1);
-                 goto retry_lock;
-               }
-#endif
-#ifdef EBUSY
-             if (errno == EBUSY)
-               {
-                 sleep (1);
-                 goto retry_lock;
-               }
-#endif
+             sleep (1);
+             goto retry_lock;
            }
 
          pfatal_with_name (inname);

=== modified file 'src/ChangeLog'
--- src/ChangeLog       2012-11-23 08:47:34 +0000
+++ src/ChangeLog       2012-11-23 08:59:17 +0000
@@ -1,3 +1,16 @@
+2012-11-23  Paul Eggert  <eggert@cs.ucla.edu>
+
+       Assume POSIX 1003.1-1988 or later for errno.h.
+       * 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.
+
 2012-11-23  Eli Zaretskii  <eliz@gnu.org>
 
        * makefile.w32-in (globals.h, gl-stamp): Use $(SWITCHCHAR) instead

=== modified file 'src/dired.c'
--- src/dired.c 2012-11-23 07:48:43 +0000
+++ src/dired.c 2012-11-23 08:56:17 +0000
@@ -193,19 +193,15 @@
 
       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 @@
 
       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);
 

=== modified file 'src/fileio.c'
--- src/fileio.c        2012-11-21 21:06:52 +0000
+++ src/fileio.c        2012-11-23 08:56:17 +0000
@@ -1995,10 +1995,8 @@
     {
       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));
        }
     }

=== modified file 'src/gmalloc.c'
--- src/gmalloc.c       2012-10-01 06:36:54 +0000
+++ src/gmalloc.c       2012-11-23 08:56:17 +0000
@@ -1645,14 +1645,6 @@
   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)
 {

=== modified file 'src/gnutls.c'
--- src/gnutls.c        2012-09-23 19:36:31 +0000
+++ src/gnutls.c        2012-11-23 08:56:17 +0000
@@ -359,12 +359,7 @@
 
   if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
     {
-#ifdef EWOULDBLOCK
-      errno = EWOULDBLOCK;
-#endif
-#ifdef EAGAIN
       errno = EAGAIN;
-#endif
       return 0;
     }
 
@@ -384,14 +379,7 @@
                 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;
            }
        }

=== modified file 'src/keyboard.c'
--- src/keyboard.c      2012-11-17 22:12:47 +0000
+++ src/keyboard.c      2012-11-23 08:56:17 +0000
@@ -6986,10 +6986,7 @@
             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

=== modified file 'src/lread.c'
--- src/lread.c 2012-11-20 20:06:17 +0000
+++ src/lread.c 2012-11-23 08:56:17 +0000
@@ -440,7 +440,6 @@
   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 @@
       clearerr (instream);
       c = getc (instream);
     }
-#endif
 
   unblock_input ();
 

=== modified file 'src/process.c'
--- src/process.c       2012-11-17 22:12:47 +0000
+++ src/process.c       2012-11-23 08:56:17 +0000
@@ -4432,14 +4432,8 @@
                  total_nread += nread;
                  got_some_input = 1;
                }
-#ifdef EIO
-             else if (nread == -1 && EIO == errno)
-               break;
-#endif
-#ifdef EAGAIN
-             else if (nread == -1 && EAGAIN == errno)
-               break;
-#endif
+             else if (nread == -1 && (errno == EIO || errno == EAGAIN))
+               break;
 #ifdef EWOULDBLOCK
              else if (nread == -1 && EWOULDBLOCK == errno)
                break;
@@ -5517,13 +5511,10 @@
 
          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

=== modified file 'src/unexcoff.c'
--- src/unexcoff.c      2012-09-15 07:06:56 +0000
+++ src/unexcoff.c      2012-11-23 08:56:17 +0000
@@ -332,11 +332,7 @@
         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