* character.h (CHAR_TO_BYTE_SAFE): New macro.

* character.c (Fmultibyte_char_to_unibyte): Obey the docstring.
* regex.c (RE_CHAR_TO_UNIBYTE): Use the new macro.
(WEAK_ALIAS): Simplify.
* syntax.c (skip_chars): Don't mark non-byte chars in the fastmap
when searching a unibyte buffer.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 8c5ebb96f28..6dc63c25537 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -1711,7 +1711,11 @@ skip_chars (forwardp, string, lim, handle_iso_classes)
               int c2 = char_ranges[i + 1];
 
               for (; c1 <= c2; c1++)
-                fastmap[CHAR_TO_BYTE8 (c1)] = 1;
+                {
+                  int b = CHAR_TO_BYTE_SAFE (c1);
+                  if (b >= 0)
+                    fastmap[b] = 1;
+                }
             }
         }
     }