(search_buffer): Give up BM search on case-fold-search

if one of a target character has a case-equivalence of different
byte length even if that target charcter is an ASCII.
(simple_search): Fix culculation of byte length of matched text.
(boyer_moore): Fix handling of case-equivalent multibyte
characters.

1 files changed, 62 insertions, 41 deletions

diff --git a/src/search.c b/src/search.c
index 29e24d75e71..0a28085308a 100644
--- a/src/search.c
+++ b/src/search.c
@@ -1141,9 +1141,9 @@ search_buffer (string, pos, pos_byte, lim, lim_byte, n,
       unsigned char *patbuf;
       int multibyte = !NILP (current_buffer->enable_multibyte_characters);
       unsigned char *base_pat = SDATA (string);
-      /* Set to nozero if we find a non-ASCII char that need
-         translation.  */
-      int char_base = 0;
+      /* Set to positive if we find a non-ASCII char that need
+         translation.  Otherwise set to zero later.  */
+      int char_base = -1;
       int boyer_moore_ok = 1;
 
       /* MULTIBYTE says whether the text to be searched is multibyte.
@@ -1234,37 +1234,46 @@ search_buffer (string, pos, pos_byte, lim, lim_byte, n,
                     {
                       /* Check if all equivalents belong to the same
                          group of characters.  Note that the check of C
-                         itself is done by the last iteration.  Note
-                         also that we don't have to check ASCII
-                         characters because boyer-moore search can
-                         always handle their translation.  */
-                      while (1)
+                         itself is done by the last iteration.  */
+                      int this_char_base = -1;
+
+                      while (boyer_moore_ok)
                         {
-                          if (! ASCII_BYTE_P (inverse))
+                          if (ASCII_BYTE_P (inverse))
                             {
-                              if (CHAR_BYTE8_P (inverse))
-                                {
-                                  /* Boyer-moore search can't handle a
-                                     translation of an eight-bit
-                                     character.  */
-                                  boyer_moore_ok = 0;
-                                  break;
-                                }
-                              else if (char_base == 0)
-                                char_base = inverse & ~0x3F;
-                              else if ((inverse & ~0x3F)
-                                       != char_base)
+                              if (this_char_base > 0)
+                                boyer_moore_ok = 0;
+                              else
                                 {
-                                  boyer_moore_ok = 0;
-                                  break;
+                                  this_char_base = 0;
+                                  if (char_base < 0)
+                                    char_base = this_char_base;
                                 }
                             }
+                          else if (CHAR_BYTE8_P (inverse))
+                            /* Boyer-moore search can't handle a
+                               translation of an eight-bit
+                               character.  */
+                            boyer_moore_ok = 0;
+                          else if (this_char_base < 0)
+                            {
+                              this_char_base = inverse & ~0x3F;
+                              if (char_base < 0)
+                                char_base = this_char_base;
+                              else if (char_base > 0
+                                       && this_char_base != char_base)
+                                boyer_moore_ok = 0;
+                            }
+                          else if ((inverse & ~0x3F) != this_char_base)
+                            boyer_moore_ok = 0;
                           if (c == inverse)
                             break;
                           TRANSLATE (inverse, inverse_trt, inverse);
                         }
                     }
                 }
+              if (char_base < 0)
+                char_base = 0;
 
               /* Store this character into the translated pattern.  */
               bcopy (str, pat, charlen);
@@ -1333,6 +1342,9 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
 {
   int multibyte = ! NILP (current_buffer->enable_multibyte_characters);
   int forward = n > 0;
+  /* Number of buffer bytes matched.  Note that this may be different
+     from len_byte in a multibyte buffer.  */
+  int match_byte;
 
   if (lim > pos && multibyte)
     while (n > 0)
@@ -1372,8 +1384,9 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
 
             if (this_len == 0)
               {
+                match_byte = this_pos_byte - pos_byte;
                 pos += len;
-                pos_byte += len_byte;
+                pos_byte += match_byte;
                 break;
               }
 
@@ -1410,6 +1423,7 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
 
             if (this_len == 0)
               {
+                match_byte = len;
                 pos += len;
                 break;
               }
@@ -1435,6 +1449,7 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
             if (pos - len < lim)
               goto stop;
             this_pos_byte = CHAR_TO_BYTE (this_pos);
+            match_byte = pos_byte - this_pos_byte;
 
             while (this_len > 0)
               {
@@ -1460,7 +1475,7 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
             if (this_len == 0)
               {
                 pos -= len;
-                pos_byte -= len_byte;
+                pos_byte -= match_byte;
                 break;
               }
 
@@ -1496,6 +1511,7 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
 
             if (this_len == 0)
               {
+                match_byte = len;
                 pos -= len;
                 break;
               }
@@ -1510,9 +1526,9 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
   if (n == 0)
     {
       if (forward)
-        set_search_regs ((multibyte ? pos_byte : pos) - len_byte, len_byte);
+        set_search_regs ((multibyte ? pos_byte : pos) - match_byte, match_byte);
       else
-        set_search_regs (multibyte ? pos_byte : pos, len_byte);
+        set_search_regs (multibyte ? pos_byte : pos, match_byte);
 
       return pos;
     }
@@ -1561,7 +1577,7 @@ boyer_moore (n, base_pat, len, len_byte, trt, inverse_trt,
 
   unsigned char simple_translate[0400];
   /* These are set to the preceding bytes of a byte to be translated
-     if charset_base is nonzero.  As the maximum byte length of a
+     if char_base is nonzero.  As the maximum byte length of a
      multibyte character is 5, we have to check at most four previous
      bytes.  */
   int translate_prev_byte1 = 0;
@@ -1662,22 +1678,31 @@ boyer_moore (n, base_pat, len, len_byte, trt, inverse_trt,
         i = infinity;
       if (! NILP (trt))
         {
-          /* If the byte currently looking at is a head of a character
-             to check case-equivalents, set CH to that character.  An
-             ASCII character and a non-ASCII character matching with
-             CHAR_BASE are to be checked.  */
+          /* If the byte currently looking at is the last of a
+             character to check case-equivalents, set CH to that
+             character.  An ASCII character and a non-ASCII character
+             matching with CHAR_BASE are to be checked.  */
           int ch = -1;
 
           if (ASCII_BYTE_P (*ptr) || ! multibyte)
             ch = *ptr;
-          else if (char_base && CHAR_HEAD_P (*ptr))
+          else if (char_base
+                   && (pat_end - ptr) == 1 || CHAR_HEAD_P (ptr[1]))
             {
-              ch = STRING_CHAR (ptr, pat_end - ptr);
+              unsigned char *charstart = ptr - 1;
+
+              while (! (CHAR_HEAD_P (*charstart)))
+                charstart--;
+              ch = STRING_CHAR (charstart, ptr - charstart + 1);
               if (char_base != (ch & ~0x3F))
                 ch = -1;
             }
 
-          j = *ptr;
+          if (ch > 0400)
+            j = (ch & 0x3F) | 0200;
+          else
+            j = *ptr;
+
           if (i == infinity)
             stride_for_teases = BM_tab[j];
 
@@ -1687,17 +1712,13 @@ boyer_moore (n, base_pat, len, len_byte, trt, inverse_trt,
           if (ch >= 0)
             {
               int starting_ch = ch;
-              int starting_j;
+              int starting_j = j;
 
-              if (ch > 0400)
-                starting_j = (ch & ~0x3F) | 0200;
-              else
-                starting_j = ch;
               while (1)
                 {
                   TRANSLATE (ch, inverse_trt, ch);
                   if (ch > 0400)
-                    j = (ch & ~0x3F) | 0200;
+                    j = (ch & 0x3F) | 0200;
                   else
                     j = ch;