Fix the current directory of the Emacs process on MS-Windows.

 src/w32.c (getwd): Adjust commentary about startup_dir.
 (init_environment): Always call sys_access, even in non-MSVC
 builds.  Don't chdir to the directory of the Emacs executable.
 This undoes code from 1997 which was justified by the need to
 "avoid conflicts when removing and renaming directories".  But its
 downside was that every relative file name was being interpreted
 relative to the directory of the Emacs executable, which can never
 be TRT.  In particular, it broke sys_access when called with
 relative file names.
 (sys_access): Map GetLastError to errno.

src/ChangeLog

+2012-06-29  Eli Zaretskii  <eliz@gnu.org>
+
+	* w32.c (getwd): Adjust commentary about startup_dir.
+	(init_environment): Always call sys_access, even in non-MSVC
+	builds.  Don't chdir to the directory of the Emacs executable.
+	This undoes code from 1997 which was justified by the need to
+	"avoid conflicts when removing and renaming directories".  But its
+	downside was that every relative file name was being interpreted
+	relative to the directory of the Emacs executable, which can never
+	be TRT.  In particular, it broke sys_access when called with
+	relative file names.
+	(sys_access): Map GetLastError to errno.
+
 2012-06-29  Dmitry Antipov  <dmantipov@yandex.ru>
 
 	* window.h (struct window): Change type of 'fringes_outside_margins'

src/w32.c

@@ -778,9 +778,8 @@ getwd (char *dir)
     return dir;
   return NULL;
 #else
-  /* Emacs doesn't actually change directory itself, and we want to
-     force our real wd to be where emacs.exe is to avoid unnecessary
-     conflicts when trying to rename or delete directories.  */
+  /* Emacs doesn't actually change directory itself, it stays in the
+     same directory where it was started.  */
   strcpy (dir, startup_dir);
   return dir;
 #endif
@@ -1536,12 +1535,7 @@ init_environment (char ** argv)
 	 read-only filesystem, like CD-ROM or a write-protected floppy.
 	 The only way to be really sure is to actually create a file and
 	 see if it succeeds.  But I think that's too much to ask.  */
-#ifdef _MSC_VER
-      /* MSVC's _access crashes with D_OK.  */
       if (tmp && sys_access (tmp, D_OK) == 0)
-#else
-      if (tmp && _access (tmp, D_OK) == 0)
-#endif
 	{
 	  char * var = alloca (strlen (tmp) + 8);
 	  sprintf (var, "TMPDIR=%s", tmp);
@@ -1781,27 +1775,15 @@ init_environment (char ** argv)
 	memcpy (*envp, "COMSPEC=", 8);
   }
 
-  /* Remember the initial working directory for getwd, then make the
-     real wd be the location of emacs.exe to avoid conflicts when
-     renaming or deleting directories.  (We also don't call chdir when
-     running subprocesses for the same reason.)  */
+  /* Remember the initial working directory for getwd.  */
   if (!GetCurrentDirectory (MAXPATHLEN, startup_dir))
     abort ();
 
   {
-    char *p;
     static char modname[MAX_PATH];
 
     if (!GetModuleFileName (NULL, modname, MAX_PATH))
       abort ();
-    if ((p = strrchr (modname, '\\')) == NULL)
-      abort ();
-    *p = 0;
-
-    SetCurrentDirectory (modname);
-
-    /* Ensure argv[0] has the full path to Emacs.  */
-    *p = '\\';
     argv[0] = modname;
   }
 
@@ -2667,7 +2649,8 @@ sys_access (const char * path, int mode)
 {
   DWORD attributes;
 
-  /* MSVC implementation doesn't recognize D_OK.  */
+  /* MSVCRT implementation of 'access' doesn't recognize D_OK, and its
+     newer versions blow up when passed D_OK.  */
   path = map_w32_filename (path, NULL);
   if (is_unc_volume (path))
     {
@@ -2679,9 +2662,17 @@ sys_access (const char * path, int mode)
     }
   else if ((attributes = GetFileAttributes (path)) == -1)
     {
-      /* Should try mapping GetLastError to errno; for now just indicate
-	 that path doesn't exist.  */
-      errno = EACCES;
+      DWORD w32err = GetLastError ();
+
+      switch (w32err)
+	{
+	case ERROR_FILE_NOT_FOUND:
+	  errno = ENOENT;
+	  break;
+	default:
+	  errno = EACCES;
+	  break;
+	}
       return -1;
     }
   if ((mode & X_OK) != 0 && !is_exec (path))