[Emacs-diffs] master 5ee3ef8: Fix handling long file names in readdir on MS-Windows

[Eli Zaretskii]

branch: master
commit 5ee3ef8e1867d284be0ff9f654f8bde46e751978
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix handling long file names in readdir on MS-Windows
    
    * src/w32.c (sys_readdir): Append "\*" to the directory after
    converting it to UTF-16/ANSI, not before, to avoid overflowing the
    260-character limit on file names in filename_to_utf16/ansi.
---
 src/w32.c |   23 ++++++++++++++++++-----
 1 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/w32.c b/src/w32.c
index 60fbe92..dea8431 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -3399,30 +3399,41 @@ sys_readdir (DIR *dirp)
   /* If we aren't dir_finding, do a find-first, otherwise do a find-next. */
   else if (dir_find_handle == INVALID_HANDLE_VALUE)
     {
-      char filename[MAX_UTF8_PATH + 2];
+      char filename[MAX_UTF8_PATH];
       int ln;
+      bool last_slash = true;
 
+      /* Note: We don't need to worry about dir_pathname being longer
+        than MAX_UTF8_PATH, as sys_opendir already took care of that
+        when it called map_w32_filename: that function will put a "?"
+        in its return value in that case, thus failing all the calls
+        below.  */
       strcpy (filename, dir_pathname);
       ln = strlen (filename);
       if (!IS_DIRECTORY_SEP (filename[ln - 1]))
-       filename[ln++] = '\\';
-      strcpy (filename + ln, "*");
+       last_slash = false;
 
       /* Note: No need to resolve symlinks in FILENAME, because
         FindFirst opens the directory that is the target of a
         symlink.  */
       if (w32_unicode_filenames)
        {
-         wchar_t fnw[MAX_PATH];
+         wchar_t fnw[MAX_PATH + 2];
 
          filename_to_utf16 (filename, fnw);
+         if (!last_slash)
+           wcscat (fnw, L"\\");
+         wcscat (fnw, L"*");
          dir_find_handle = FindFirstFileW (fnw, &dir_find_data_w);
        }
       else
        {
-         char fna[MAX_PATH];
+         char fna[MAX_PATH + 2];
 
          filename_to_ansi (filename, fna);
+         if (!last_slash)
+           strcat (fna, "\\");
+         strcat (fna, "*");
          /* If FILENAME is not representable by the current ANSI
             codepage, we don't want FindFirstFileA to interpret the
             '?' characters as a wildcard.  */
@@ -3860,6 +3871,8 @@ w32_accessible_directory_p (const char *dirname, 
ptrdiff_t dirlen)
   bool last_slash = dirlen > 0 && IS_DIRECTORY_SEP (dirname[dirlen - 1]);
   HANDLE dh;
 
+  /* Note: map_w32_filename makes sure DIRNAME is not longer than
+     MAX_UTF8_PATH.  */
   strcpy (pattern, map_w32_filename (dirname, NULL));
 
   /* Note: No need to resolve symlinks in FILENAME, because FindFirst