# HG changeset patch
# User stephent
# Date 1110344371 0
# Node ID cd00e5eeb22a13751e862b39db1007705b35edb0
# Parent  94aad03d0e1edd65b152470fae9d3df3a8e8c19c
[xemacs-hg @ 2005-03-09 04:59:25 by stephent]
small regex doc patch <876501fmab.fsf@tleepslib.sk.tsukuba.ac.jp>

diff -r 94aad03d0e1e -r cd00e5eeb22a src/ChangeLog
--- a/src/ChangeLog	Tue Mar 08 22:51:29 2005 +0000
+++ b/src/ChangeLog	Wed Mar 09 04:59:31 2005 +0000
@@ -1,3 +1,9 @@
+2005-01-13  Stephen J. Turnbull  <stephen@xemacs.org>
+
+	* regex.c (re_match_2_internal): 
+	* regex.h (struct re_pattern_buffer):
+	Improve comments.  Add a DEBUG_PRINT2 for null matches.
+
 2005-03-02  Aidan Kehoe  <kehoea@parhasard.net>
 
 	* select-x.c (x_reply_selection_request): Check that
diff -r 94aad03d0e1e -r cd00e5eeb22a src/regex.c
--- a/src/regex.c	Tue Mar 08 22:51:29 2005 +0000
+++ b/src/regex.c	Wed Mar 09 04:59:31 2005 +0000
@@ -5178,8 +5178,9 @@
 				    : ((regoff_t) (d - string2 + size1)));
 		  }
 
-		/* Go through the first `min (num_regs, regs->num_regs)'
-		   registers, since that is all we initialized.  */
+		/* Map over the NUM_NONSHY_REGS non-shy internal registers.
+		   Copy each into the corresponding external register.
+		   MCNT indexes external registers. */
 		for (mcnt = 1; mcnt < MIN (num_nonshy_regs, regs->num_regs);
 		     mcnt++)
 		  {
@@ -5198,9 +5199,10 @@
 	      } /* regs && !bufp->no_sub */
 
 	    /* If we have regs and the regs structure has more elements than
-	       were in the pattern, set the extra elements to -1.  If we
-	       (re)allocated the registers, this is the case, because we
-	       always allocate enough to have at least one -1 at the end.
+	       were in the pattern, set the extra elements starting with
+	       NUM_NONSHY_REGS to -1.  If we (re)allocated the registers,
+	       this is the case, because we always allocate enough to have
+	       at least one -1 at the end.
 
 	       We do this even when no_sub is set because some applications
 	       (XEmacs) reuse register structures which may contain stale
@@ -5406,8 +5408,11 @@
 	  p1 = p;		/* To send to group_match_null_string_p.  */
 
           if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
-            REG_MATCH_NULL_STRING_P (reg_info[*p])
-              = group_match_null_string_p (&p1, pend, reg_info);
+	    REG_MATCH_NULL_STRING_P (reg_info[*p])
+	      = group_match_null_string_p (&p1, pend, reg_info);
+
+	  DEBUG_PRINT2 ("  group CAN%s match null string\n",
+			REG_MATCH_NULL_STRING_P (reg_info[*p]) ? "NOT" : "");
 
           /* Save the position in the string where we were the last time
              we were at this open-group operator in case the group is
diff -r 94aad03d0e1e -r cd00e5eeb22a src/regex.h
--- a/src/regex.h	Tue Mar 08 22:51:29 2005 +0000
+++ b/src/regex.h	Wed Mar 09 04:59:31 2005 +0000
@@ -357,8 +357,8 @@
            when it is matched.  */
   RE_TRANSLATE_TYPE translate;
 
-	/* Number of returnable groups found by the compiler. (This does
-           not count shy groups.) */
+	/* Number of subpatterns (returnable groups) found by the compiler.
+	   (This does not count shy groups.) */
   int re_nsub;
 
 	/* Total number of groups found by the compiler. (Including