3 files changed, 52 insertions, 17 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a33e834e0ec..dc495089739 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2015-01-28  Eli Zaretskii  <eliz@gnu.org>
+
+        * dired.c (directory_files_internal, file_name_completion)
+        [WINDOWSNT]: Signal an error when errno is set non-zero by
+        'readdir', regardless of its value.
+
+        * w32.c (sys_readdir): Set errno to ENOENT when the directory
+        doesn't exist and to EACCES when it's not accessible to the
+        current user.  Set errno to zero when FindNextFile exhausts the
+        directory, so that callers don't interpret that as an error and
+        don't signal a file-error.
+        (open_unc_volume): Set errno to ENOENT if WNetOpenEnum fails.
+
 2015-01-27  Eli Zaretskii  <eliz@gnu.org>
 
         * dired.c (directory_files_internal) [WINDOWSNT]: If readdir
diff --git a/src/dired.c b/src/dired.c
index f6c47a71400..43cb8373a6d 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -251,14 +251,9 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
           /* The MS-Windows implementation of 'opendir' doesn't
              actually open a directory until the first call to
              'readdir'.  If 'readdir' fails to open the directory, it
-             sets errno to ENOTDIR; we convert it here to ENOENT so
-             that the error message is similar to what happens on
-             Posix hosts in such cases.  */
-          if (errno == ENOTDIR)
-            {
-              errno = ENOENT;
-              report_file_error ("Opening directory", directory);
-            }
+             sets errno to ENOENT or EACCES, see w32.c.  */
+          if (errno)
+            report_file_error ("Opening directory", directory);
 #endif
           break;
         }
@@ -530,6 +525,10 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
               QUIT;
               continue;
             }
+#ifdef WINDOWSNT
+          if (errno)
+            report_file_error ("Opening directory", dirname);
+#endif
           break;
         }
 
diff --git a/src/w32.c b/src/w32.c
index aedf64942e0..2faa742f9d7 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -3433,17 +3433,30 @@ sys_readdir (DIR *dirp)
 
       if (dir_find_handle == INVALID_HANDLE_VALUE)
         {
+          /* Any changes in the value of errno here should be in sync
+             with what directory_files_internal does when it calls
+             readdir.  */
           switch (GetLastError ())
             {
-            case ERROR_PATH_NOT_FOUND:
+              /* Windows uses this value when FindFirstFile finds no
+                 files that match the wildcard.  This is not supposed
+                 to happen, since our wildcard is "*", but just in
+                 case, if there's some weird empty directory with not
+                 even "." and ".." entries...  */
+            case ERROR_FILE_NOT_FOUND:
+              errno = 0;
+              /* FALLTHRU */
+            default:
+              break;
             case ERROR_ACCESS_DENIED:
+            case ERROR_NETWORK_ACCESS_DENIED:
+              errno = EACCES;
+              break;
+            case ERROR_PATH_NOT_FOUND:
             case ERROR_INVALID_DRIVE:
             case ERROR_BAD_NETPATH:
-              /* This special value will be noticed by
-                 directory_files_internal, which see.  */
-              errno = ENOTDIR;
-              break;
-            default:
+            case ERROR_BAD_NET_NAME:
+              errno = ENOENT;
               break;
             }
           return NULL;
@@ -3452,12 +3465,18 @@ sys_readdir (DIR *dirp)
   else if (w32_unicode_filenames)
     {
       if (!FindNextFileW (dir_find_handle, &dir_find_data_w))
-        return NULL;
+        {
+          errno = 0;
+          return NULL;
+        }
     }
   else
     {
       if (!FindNextFileA (dir_find_handle, &dir_find_data_a))
-        return NULL;
+        {
+          errno = 0;
+          return NULL;
+        }
     }
 
   /* Emacs never uses this value, so don't bother making it match
@@ -3559,7 +3578,11 @@ open_unc_volume (const char *path)
   if (result == NO_ERROR)
     return henum;
   else
-    return INVALID_HANDLE_VALUE;
+    {
+      /* Make sure directory_files_internal reports a sensible error.  */
+      errno = ENOENT;
+      return INVALID_HANDLE_VALUE;
+    }
 }
 
 static void *