1 files changed, 66 insertions, 35 deletions

diff --git a/src/dired.c b/src/dired.c
index 3768b6dbb7c..0e1c88f03ce 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -481,18 +481,32 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
   record_unwind_protect_ptr (directory_files_internal_unwind, d);
 
   /* Loop reading directory entries.  */
+  Lisp_Object zero = make_fixnum (0);
+  ptrdiff_t enc_file_len = SCHARS (encoded_file);
+  Lisp_Object file_len = make_fixnum (SCHARS (file));
   for (struct dirent *dp; (dp = read_dirent (d, dirname)); )
     {
       ptrdiff_t len = dirent_namelen (dp);
       bool canexclude = 0;
 
       maybe_quit ();
-      if (len < SCHARS (encoded_file)
-          || (scmp (dp->d_name, SSDATA (encoded_file),
-                    SCHARS (encoded_file))
-              >= 0))
+
+      if (len < enc_file_len
+          /* scmp cannot reliably compare non-ASCII strings while
+             ignoring letter-case.  */
+          || (!completion_ignore_case
+              && scmp (dp->d_name, SSDATA (encoded_file), enc_file_len) >= 0))
         continue;
 
+      name = make_unibyte_string (dp->d_name, len);
+      name = DECODE_FILE (name);
+      ptrdiff_t name_blen = SBYTES (name), name_len = SCHARS (name);
+      if (completion_ignore_case
+          && !EQ (Fcompare_strings (name, zero, file_len, file, zero, file_len,
+                                    Qt),
+                  Qt))
+            continue;
+
       switch (dirent_type (dp))
         {
         case DT_DIR:
@@ -515,6 +529,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
       if (!all_flag)
         {
           ptrdiff_t skip;
+          Lisp_Object cmp_len = make_fixnum (name_len);
 
 #if 0 /* FIXME: The `scmp' call compares an encoded and a decoded string. */
           /* If this entry matches the current bestmatch, the only
@@ -538,7 +553,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                  actually in the way in a directory with only one file.  */
               if (TRIVIAL_DIRECTORY_ENTRY (dp->d_name))
                 canexclude = 1;
-              else if (len > SCHARS (encoded_file))
+              else if (len > enc_file_len)
                 /* Ignore directories if they match an element of
                    completion-ignored-extensions which ends in a slash.  */
                 for (tem = Vcompletion_ignored_extensions;
@@ -550,21 +565,31 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                     elt = XCAR (tem);
                     if (!STRINGP (elt))
                       continue;
-                    /* Need to encode ELT, since scmp compares unibyte
-                       strings only.  */
-                    elt = ENCODE_FILE (elt);
-                    elt_len = SCHARS (elt) - 1; /* -1 for trailing / */
+                    elt_len = SBYTES (elt) - 1; /* -1 for trailing / */
                     if (elt_len <= 0)
                       continue;
                     p1 = SSDATA (elt);
                     if (p1[elt_len] != '/')
                       continue;
-                    skip = len - elt_len;
+                    skip = name_blen - elt_len;
                     if (skip < 0)
                       continue;
 
-                    if (scmp (dp->d_name + skip, p1, elt_len) >= 0)
+                    if (!completion_ignore_case
+                        && scmp (SSDATA (name) + skip, p1, elt_len) >= 0)
                       continue;
+                    if (completion_ignore_case)
+                      {
+                        elt_len = SCHARS (elt) - 1;
+                        skip = name_len - elt_len;
+                        cmp_len = make_fixnum (elt_len);
+                        if (skip < 0
+                            || !EQ (Fcompare_strings (name, make_fixnum (skip),
+                                                      cmp_len,
+                                                      elt, zero, cmp_len, Qt),
+                                    Qt))
+                          continue;
+                      }
                     break;
                   }
             }
@@ -572,22 +597,33 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
             {
               /* Compare extensions-to-be-ignored against end of this file name */
               /* if name is not an exact match against specified string */
-              if (len > SCHARS (encoded_file))
+              if (len > enc_file_len)
                 /* and exit this for loop if a match is found */
                 for (tem = Vcompletion_ignored_extensions;
                      CONSP (tem); tem = XCDR (tem))
                   {
                     elt = XCAR (tem);
                     if (!STRINGP (elt)) continue;
-                    /* Need to encode ELT, since scmp compares unibyte
-                       strings only.  */
-                    elt = ENCODE_FILE (elt);
-                    skip = len - SCHARS (elt);
+                    ptrdiff_t elt_len = SBYTES (elt);
+                    skip = len - elt_len;
                     if (skip < 0) continue;
 
-                    if (scmp (dp->d_name + skip, SSDATA (elt), SCHARS (elt))
-                        >= 0)
+                    if (!completion_ignore_case
+                        && (scmp (SSDATA (name) + skip, SSDATA (elt), elt_len)
+                            >= 0))
                       continue;
+                    if (completion_ignore_case)
+                      {
+                        elt_len = SCHARS (elt);
+                        skip = name_len - elt_len;
+                        cmp_len = make_fixnum (elt_len);
+                        if (skip < 0
+                            || !EQ (Fcompare_strings (name, make_fixnum (skip),
+                                                      cmp_len,
+                                                      elt, zero, cmp_len, Qt),
+                                    Qt))
+                          continue;
+                      }
                     break;
                   }
             }
@@ -611,24 +647,18 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
               matchcount = 0;
             }
         }
-      /* FIXME: If we move this `decode' earlier we can eliminate
-         the repeated ENCODE_FILE on Vcompletion_ignored_extensions.  */
-      name = make_unibyte_string (dp->d_name, len);
-      name = DECODE_FILE (name);
 
-      {
-        Lisp_Object regexps, table = (completion_ignore_case
-                                      ? Vascii_canon_table : Qnil);
+      Lisp_Object regexps, table = (completion_ignore_case
+                                    ? Vascii_canon_table : Qnil);
 
-        /* Ignore this element if it fails to match all the regexps.  */
-        for (regexps = Vcompletion_regexp_list; CONSP (regexps);
-             regexps = XCDR (regexps))
-          if (fast_string_match_internal (XCAR (regexps), name, table) < 0)
-            break;
+      /* Ignore this element if it fails to match all the regexps.  */
+      for (regexps = Vcompletion_regexp_list; CONSP (regexps);
+           regexps = XCDR (regexps))
+        if (fast_string_match_internal (XCAR (regexps), name, table) < 0)
+          break;
 
-        if (CONSP (regexps))
-          continue;
-      }
+      if (CONSP (regexps))
+        continue;
 
       /* This is a possible completion */
       if (directoryp)
@@ -642,8 +672,6 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
       /* Reject entries where the encoded strings match, but the
          decoded don't.  For example, "a" should not match "a-ring" on
          file systems that store decomposed characters. */
-      Lisp_Object zero = make_fixnum (0);
-
       if (check_decoded && SCHARS (file) <= SCHARS (name))
         {
           /* FIXME: This is a copy of the code below.  */
@@ -757,6 +785,9 @@ scmp (const char *s1, const char *s2, ptrdiff_t len)
 
   if (completion_ignore_case)
     {
+      /* WARNING: This only works for pure ASCII strings, as we
+         compare bytes, not characters!  Use Fcompare_strings for
+         comparing non-ASCII strings case-insensitively.  */
       while (l
              && (downcase ((unsigned char) *s1++)
                  == downcase ((unsigned char) *s2++)))