From: Gurusamy Sarathy <gsar@engin.umich.edu>
Date: Sat, 21 Dec 1996 02:59:22 +0000 (-0500)
Subject: patch for regex bug: (x|x){n}
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=579cf2c30d1c2eed351c0a6945d08a57bdcd1f6b;p=p5sagit%2Fp5-mst-13.2.git

patch for regex bug: (x|x){n}

On Mon, 16 Dec 1996 18:04:08 EST, I wrote:
>
>7.  Symmetry confounds quantified regex alternation
>
>A well-researched bug report sent in by Charles Bailey:
>
>     Message-Id: <01IA10O8ZIB600219C@hmivax.humgen.upenn.edu>,
>     Subject: Regex bug: (x|x){n}
>
>Pity I didn't have time to take a closer look at that one.

Here's a patch for the problem reported in the reference above.

Simpler test cases:

  % perl -we '$_ = "atatttta"; print "|$1|$2|\n" if /((t|t){3})/;'

says "|t||" instead of instead of "|ttt|t|"; and

  % perl -we '$_ = "atatttta"; print "|$1|$2|\n" if /((t|t){3,})/;'

says "|t||" instead of instead of "|tttt|t|"; and

p5p-msgid: <199612210259.VAA10170@aatma.engin.umich.edu>
---

diff --git a/regexec.c b/regexec.c
index 292f960..bed5a99 100644
--- a/regexec.c
+++ b/regexec.c
@@ -891,7 +891,7 @@ char *prog;
 
 		/* If degenerate scan matches "", assume scan done. */
 
-		if (locinput == cc->lastloc) {
+		if (locinput == cc->lastloc && n >= cc->min) {
 		    regcc = cc->oldcc;
 		    ln = regcc->cur;
 		    if (regmatch(cc->next))