From: Yves Orton <demerphq@gmail.com>
Date: Sun, 17 Feb 2008 15:39:22 +0000 (+0000)
Subject: Fix perlbug 50114 and document what the code does a bit better
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=639081d6f95c9b3121be1c0c372070f2e0ca4eaf;p=p5sagit%2Fp5-mst-13.2.git

Fix perlbug 50114 and document what the code does a bit better

p4raw-id: //depot/perl@33324
---

diff --git a/regcomp.c b/regcomp.c
index 1959730..c4313ae 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4462,7 +4462,17 @@ reStudy:
         regnode *first= scan;
         regnode *first_next= regnext(first);
 	
-	/* Skip introductions and multiplicators >= 1. */
+	/*
+	 * Skip introductions and multiplicators >= 1
+	 * so that we can extract the 'meat' of the pattern that must 
+	 * match in the large if() sequence following.
+	 * NOTE that EXACT is NOT covered here, as it is normally
+	 * picked up by the optimiser separately. 
+	 *
+	 * This is unfortunate as the optimiser isnt handling lookahead
+	 * properly currently.
+	 *
+	 */
 	while ((OP(first) == OPEN && (sawopen = 1)) ||
 	       /* An OR of *one* alternative - should not happen now. */
 	    (OP(first) == BRANCH && OP(first_next) != BRANCH) ||
@@ -4474,16 +4484,17 @@ reStudy:
 	    (PL_regkind[OP(first)] == CURLY && ARG1(first) > 0) ||
 	    (OP(first) == NOTHING && PL_regkind[OP(first_next)] != END ))
 	{
-	        
+		/* 
+		 * the only op that could be a regnode is PLUS, all the rest
+		 * will be regnode_1 or regnode_2.
+		 *
+		 */
 		if (OP(first) == PLUS)
 		    sawplus = 1;
 		else
 		    first += regarglen[OP(first)];
-		if (OP(first) == IFMATCH) {
-		    first = NEXTOPER(first);
-		    first += EXTRA_STEP_2ARGS;
-		} else  /* XXX possible optimisation for /(?=)/  */
-		    first = NEXTOPER(first);
+		
+		first = NEXTOPER(first);
 		first_next= regnext(first);
 	}
 
diff --git a/t/op/re_tests b/t/op/re_tests
index c2397e6..3df3745 100644
--- a/t/op/re_tests
+++ b/t/op/re_tests
@@ -1341,3 +1341,6 @@ foo(\h)bar	foo\tbar	y	$1	\t
 .*\z	foo\n	y	-	-
 ^(?:(\d)x)?\d$	1	y	${\(defined($1)?1:0)}	0	
 .*?(?:(\w)|(\w))x	abx	y	$1-$2	b-
+
+0{50}	000000000000000000000000000000000000000000000000000	y	-	-
+