(analyse_first): For eight-bit-control chars, mark both the

char's value and its leading byte in the fastmap.
(re_search_2): When fast-scanning without translation, be careful to
check that we only match the leading byte of a multibyte char.

1 files changed, 42 insertions, 8 deletions

diff --git a/src/regex.c b/src/regex.c
index 763b490c906..66e363e731c 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -3877,11 +3877,13 @@ analyse_first (p, pend, fastmap, multibyte)
           if (fastmap)
             {
               int c = RE_STRING_CHAR (p + 1, pend - p);
-
+              /* When fast-scanning, the fastmap can be indexed either with
+                 a char (smaller than 256) or with the first byte of
+                 a char's byte sequence.  So we have to conservatively add
+                 both to the table.  */
               if (SINGLE_BYTE_CHAR_P (c))
                 fastmap[c] = 1;
-              else
-                fastmap[p[1]] = 1;
+              fastmap[p[1]] = 1;
             }
           break;
 
@@ -3899,6 +3901,10 @@ analyse_first (p, pend, fastmap, multibyte)
              So any that are not listed in the charset
              are possible matches, even in multibyte buffers.  */
           if (!fastmap) break;
+          /* We don't need to mark LEADING_CODE_8_BIT_CONTROL specially
+             because it will automatically be set when needed by virtue of
+             being larger than the highest char of its charset (0xbf) but
+             smaller than (1<<BYTEWIDTH).  */
           for (j = CHARSET_BITMAP_SIZE (&p[-1]) * BYTEWIDTH;
                j < (1 << BYTEWIDTH); j++)
             fastmap[j] = 1;
@@ -3909,7 +3915,13 @@ analyse_first (p, pend, fastmap, multibyte)
           for (j = CHARSET_BITMAP_SIZE (&p[-1]) * BYTEWIDTH - 1, p++;
                j >= 0; j--)
             if (!!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) ^ not)
-              fastmap[j] = 1;
+              {
+                fastmap[j] = 1;
+#ifdef emacs
+                if (j >= 0x80 && j < 0xa0)
+                  fastmap[LEADING_CODE_8_BIT_CONTROL] = 1;
+#endif
+              }
 
           if ((not && multibyte)
               /* Any character set can possibly contain a character
@@ -4352,11 +4364,33 @@ re_search_2 (bufp, str1, size1, str2, size2, startpos, range, regs, stop)
                     }
                 }
               else
-                while (range > lim && !fastmap[*d])
+                do
                   {
-                    d++;
-                    range--;
-                  }
+                    re_char *d_start = d;
+                    while (range > lim && !fastmap[*d])
+                      {
+                        d++;
+                        range--;
+                      }
+#ifdef emacs
+                    if (multibyte && range > lim)
+                      {
+                        /* Check that we are at the beginning of a char.  */
+                        int at_boundary;
+                        AT_CHAR_BOUNDARY_P (at_boundary, d, d_start);
+                        if (at_boundary)
+                          break;
+                        else
+                          { /* We have matched an internal byte of a char
+                               rather than the leading byte, so it's a false
+                               positive: we should keep scanning.  */
+                            d++; range--;
+                          }
+                      }
+                    else
+#endif
+                      break;
+                  } while (1);
 
               startpos += irange - range;
             }