[Emacs-diffs] master 81d6418: Fix file-name-case-insensitive-p on non-existent files

[Ken Brown]

branch: master
commit 81d6418e6b7c3e637dccf9c856d9c4b94bd43b97
Author: Ken Brown <address@hidden>
Commit: Ken Brown <address@hidden>

    Fix file-name-case-insensitive-p on non-existent files
    
    * src/fileio.c (Ffile_name_case_insensitive_p): If the file
    doesn't exist, move up the filesystem tree until an existing
    directory is found.  Then test that directory for
    case-insensitivity.  (Bug#32246)
---
 src/fileio.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/fileio.c b/src/fileio.c
index b92492c..2dcfb73 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2296,6 +2296,21 @@ The arg must be a string.  */)
   if (!NILP (handler))
     return call2 (handler, Qfile_name_case_insensitive_p, filename);
 
+  /* If the file doesn't exist, move up the filesystem tree until we
+     reach an existing directory or the root.  */
+  if (NILP (Ffile_exists_p (filename)))
+    {
+      filename = Ffile_name_directory (filename);
+      while (NILP (Ffile_exists_p (filename)))
+       {
+         Lisp_Object newname = expand_and_dir_to_file (filename);
+         /* Avoid infinite loop if the root is reported as non-existing
+            (impossible?).  */
+         if (!NILP (Fstring_equal (newname, filename)))
+           break;
+         filename = newname;
+       }
+    }
   filename = ENCODE_FILE (filename);
   return file_name_case_insensitive_p (SSDATA (filename)) ? Qt : Qnil;
 }