[Emacs-diffs] /srv/bzr/emacs/trunk r110896: MS-Windows followup for revision 110889, regarding faccessat.

[Eli Zaretskii]

------------------------------------------------------------
revno: 110896
fixes bug: http://debbugs.gnu.org/12632
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Wed 2012-11-14 19:22:55 +0200
message:
  MS-Windows followup for revision 110889, regarding faccessat.
  
   nt/inc/unistd.h (faccessat): Add prototype.
   (AT_FDCWD, AT_EACCESS, AT_SYMLINK_NOFOLLOW): New macros; the first
   2 moved from ms-w32.h.
   nt/inc/ms-w32.h (AT_FDCWD, AT_EACCESS, faccessat): Remove macros.
  
   src/w32.c (faccessat): Rename from sys_faccessat.  (No need to use a
   different name, as the MS runtime does not have such a function,
   and probably never will.)  All callers changed.  Ignore DIRFD
   value if PATH is an absolute file name, to match Posix spec
   better.  If AT_SYMLINK_NOFOLLOW is set in FLAGS, don't resolve
   symlinks.
modified:
  nt/ChangeLog
  nt/inc/ms-w32.h
  nt/inc/unistd.h
  src/ChangeLog
  src/w32.c

=== modified file 'nt/ChangeLog'
--- a/nt/ChangeLog      2012-11-14 04:55:41 +0000
+++ b/nt/ChangeLog      2012-11-14 17:22:55 +0000
@@ -1,3 +1,11 @@
+2012-11-14  Eli Zaretskii  <address@hidden>
+
+       * inc/unistd.h (faccessat): Add prototype.
+       (AT_FDCWD, AT_EACCESS, AT_SYMLINK_NOFOLLOW): New macros; the first
+       2 moved from ms-w32.h.
+
+       * inc/ms-w32.h (AT_FDCWD, AT_EACCESS, faccessat): Remove macros.
+
 2012-11-14  Paul Eggert  <address@hidden>
 
        Use faccessat, not access, when checking file permissions (Bug#12632).

=== modified file 'nt/inc/ms-w32.h'
--- a/nt/inc/ms-w32.h   2012-11-14 04:55:41 +0000
+++ b/nt/inc/ms-w32.h   2012-11-14 17:22:55 +0000
@@ -124,10 +124,6 @@
 #define MAXPATHLEN      _MAX_PATH
 #endif
 
-/* Use values compatible with gnulib, as there's no reason to differ.  */
-#define AT_FDCWD (-3041965)
-#define AT_EACCESS 4
-
 #ifdef HAVE_NTGUI
 #define HAVE_WINDOW_SYSTEM 1
 #define HAVE_MENUS 1
@@ -163,7 +159,6 @@
 #define dup     sys_dup
 #undef dup2
 #define dup2    sys_dup2
-#define faccessat  sys_faccessat
 #define fopen   sys_fopen
 #define link    sys_link
 #define localtime sys_localtime

=== modified file 'nt/inc/unistd.h'
--- a/nt/inc/unistd.h   2012-11-05 17:29:30 +0000
+++ b/nt/inc/unistd.h   2012-11-14 17:22:55 +0000
@@ -18,4 +18,12 @@
 extern pid_t setsid (void);
 extern pid_t tcgetpgrp (int);
 
+extern int faccessat (int, char const *, int, int);
+
+/* These are normally on fcntl.h, but we don't override that header.  */
+/* Use values compatible with gnulib, as there's no reason to differ.  */
+#define AT_FDCWD (-3041965)
+#define AT_EACCESS 4
+#define AT_SYMLINK_NOFOLLOW 4096
+
 #endif /* _UNISTD_H */

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-11-14 11:13:33 +0000
+++ b/src/ChangeLog     2012-11-14 17:22:55 +0000
@@ -1,3 +1,12 @@
+2012-11-14  Eli Zaretskii  <address@hidden>
+
+       * w32.c (faccessat): Rename from sys_faccessat.  (No need to use a
+       different name, as the MS runtime does not have such a function,
+       and probably never will.)  All callers changed.  Ignore DIRFD
+       value if PATH is an absolute file name, to match Posix spec
+       better.  If AT_SYMLINK_NOFOLLOW is set in FLAGS, don't resolve
+       symlinks.
+
 2012-11-14  Dmitry Antipov  <address@hidden>
 
        * xdisp.c (echo_area_display, redisplay_internal):

=== modified file 'src/w32.c'
--- a/src/w32.c 2012-11-14 04:55:41 +0000
+++ b/src/w32.c 2012-11-14 17:22:55 +0000
@@ -1597,7 +1597,7 @@
         see if it succeeds.  But I think that's too much to ask.  */
 
       /* MSVCRT's _access crashes with D_OK.  */
-      if (tmp && sys_faccessat (AT_FDCWD, tmp, D_OK, AT_EACCESS) == 0)
+      if (tmp && faccessat (AT_FDCWD, tmp, D_OK, AT_EACCESS) == 0)
        {
          char * var = alloca (strlen (tmp) + 8);
          sprintf (var, "TMPDIR=%s", tmp);
@@ -2708,17 +2708,15 @@
   WNetAddConnection2 (&resource, NULL, NULL, CONNECT_INTERACTIVE);
 }
 
-/* Shadow some MSVC runtime functions to map requests for long filenames
-   to reasonable short names if necessary.  This was originally added to
-   permit running Emacs on NT 3.1 on a FAT partition, which doesn't support
-   long file names.  */
-
+/* Emulate faccessat(2).  */
 int
-sys_faccessat (int dirfd, const char * path, int mode, int flags)
+faccessat (int dirfd, const char * path, int mode, int flags)
 {
   DWORD attributes;
 
-  if (dirfd != AT_FDCWD)
+  if (dirfd != AT_FDCWD
+      && !(IS_DIRECTORY_SEP (path[0])
+          || IS_DEVICE_SEP (path[1])))
     {
       errno = EBADF;
       return -1;
@@ -2731,7 +2729,8 @@
      to get the attributes of its target file.  Note: any symlinks in
      PATH elements other than the last one are transparently resolved
      by GetFileAttributes below.  */
-  if ((volume_info.flags & FILE_SUPPORTS_REPARSE_POINTS) != 0)
+  if ((volume_info.flags & FILE_SUPPORTS_REPARSE_POINTS) != 0
+      && (flags & AT_SYMLINK_NOFOLLOW) == 0)
     path = chase_symlinks (path);
 
   if ((attributes = GetFileAttributes (path)) == -1)
@@ -2781,6 +2780,11 @@
   return 0;
 }
 
+/* Shadow some MSVC runtime functions to map requests for long filenames
+   to reasonable short names if necessary.  This was originally added to
+   permit running Emacs on NT 3.1 on a FAT partition, which doesn't support
+   long file names.  */
+
 int
 sys_chdir (const char * path)
 {
@@ -2966,7 +2970,7 @@
        {
          int save_errno = errno;
          p[0] = first_char[i];
-         if (sys_faccessat (AT_FDCWD, template, F_OK, AT_EACCESS) < 0)
+         if (faccessat (AT_FDCWD, template, F_OK, AT_EACCESS) < 0)
            {
              errno = save_errno;
              return template;
@@ -4017,7 +4021,7 @@
     {
       /* Non-absolute FILENAME is understood as being relative to
         LINKNAME's directory.  We need to prepend that directory to
-        FILENAME to get correct results from sys_faccessat below, since
+        FILENAME to get correct results from faccessat below, since
         otherwise it will interpret FILENAME relative to the
         directory where the Emacs process runs.  Note that
         make-symbolic-link always makes sure LINKNAME is a fully
@@ -4031,10 +4035,10 @@
        strncpy (tem, linkfn, p - linkfn);
       tem[p - linkfn] = '\0';
       strcat (tem, filename);
-      dir_access = sys_faccessat (AT_FDCWD, tem, D_OK, AT_EACCESS);
+      dir_access = faccessat (AT_FDCWD, tem, D_OK, AT_EACCESS);
     }
   else
-    dir_access = sys_faccessat (AT_FDCWD, filename, D_OK, AT_EACCESS);
+    dir_access = faccessat (AT_FDCWD, filename, D_OK, AT_EACCESS);
 
   /* Since Windows distinguishes between symlinks to directories and
      to files, we provide a kludgy feature: if FILENAME doesn't