* buffer.h (FETCH_MULTIBYTE_CHAR): Define as inline.

[bpt/emacs.git] / src / regex.c

diff --git a/src/regex.c b/src/regex.c
index f9a12a3..7ef53c6 100644 (file)
--- a/src/regex.c
+++ b/src/regex.c
@@ -130,13 +130,13 @@
 
 # include <setjmp.h>
 # include "lisp.h"
+# include "character.h"
 # include "buffer.h"
 
 /* Make syntax table lookup grant data in gl_state.  */
 # define SYNTAX_ENTRY_VIA_PROPERTY
 
 # include "syntax.h"
-# include "character.h"
 # include "category.h"
 
 # ifdef malloc
@@ -3824,18 +3824,37 @@ static boolean
 at_begline_loc_p (const re_char *pattern, const re_char *p, reg_syntax_t syntax)
 {
   re_char *prev = p - 2;
-  boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
+  boolean odd_backslashes;
 
-  return
-       /* After a subexpression?  */
-       (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
-       /* After an alternative?         */
-    || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash))
-       /* After a shy subexpression?  */
-    || ((syntax & RE_SHY_GROUPS) && prev - 2 >= pattern
-       && prev[-1] == '?' && prev[-2] == '('
-       && (syntax & RE_NO_BK_PARENS
-           || (prev - 3 >= pattern && prev[-3] == '\\')));
+  /* After a subexpression?  */
+  if (*prev == '(')
+    odd_backslashes = (syntax & RE_NO_BK_PARENS) == 0;
+
+  /* After an alternative?  */
+  else if (*prev == '|')
+    odd_backslashes = (syntax & RE_NO_BK_VBAR) == 0;
+
+  /* After a shy subexpression?  */
+  else if (*prev == ':' && (syntax & RE_SHY_GROUPS))
+    {
+      /* Skip over optional regnum.  */
+      while (prev - 1 >= pattern && prev[-1] >= '0' && prev[-1] <= '9')
+       --prev;
+
+      if (!(prev - 2 >= pattern
+           && prev[-1] == '?' && prev[-2] == '('))
+       return false;
+      prev -= 2;
+      odd_backslashes = (syntax & RE_NO_BK_PARENS) == 0;
+    }
+  else
+    return false;
+
+  /* Count the number of preceding backslashes.  */
+  p = prev;
+  while (prev - 1 >= pattern && prev[-1] == '\\')
+    --prev;
+  return (p - prev) & odd_backslashes;
 }