From: Hugo van der Sanden <hv@crypt.org>
Date: Mon, 23 Oct 2000 00:47:22 +0000 (+0100)
Subject: Re: [ID 20001021.005] SEGV with regex match
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=a1933d9520524187cd6ffbd1408c92d37eba7fe2;p=p5sagit%2Fp5-mst-13.2.git

Re: [ID 20001021.005] SEGV with regex match
Message-Id: <200010222347.AAA09697@crypt.compulink.co.uk>

p4raw-id: //depot/perl@7407
---

diff --git a/regexec.c b/regexec.c
index d3f2065..6e046f3 100644
--- a/regexec.c
+++ b/regexec.c
@@ -325,6 +325,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     register I32 end_shift;
     register char *s;
     register SV *check;
+    char *strbeg;
     char *t;
     I32 ml_anch;
     char *tmp;
@@ -351,6 +352,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 	DEBUG_r(PerlIO_printf(Perl_debug_log, "String too short...\n"));
 	goto fail;
     }
+    strbeg = (sv && SvPOK(sv)) ? strend - SvCUR(sv) : strpos;
     check = prog->check_substr;
     if (prog->reganch & ROPT_ANCH) {	/* Match at beg-of-str or after \n */
 	ml_anch = !( (prog->reganch & ROPT_ANCH_SINGLE)
@@ -361,7 +363,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 	  if ( !(prog->reganch & ROPT_ANCH_GPOS) /* Checked by the caller */
 	       /* SvCUR is not set on references: SvRV and SvPVX overlap */
 	       && sv && !SvROK(sv)
-	       && (strpos + SvCUR(sv) != strend)) {
+	       && (strpos != strbeg)) {
 	      DEBUG_r(PerlIO_printf(Perl_debug_log, "Not at start...\n"));
 	      goto fail;
 	  }
@@ -428,7 +430,6 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     /* Find a possible match in the region s..strend by looking for
        the "check" substring in the region corrected by start/end_shift. */
     if (flags & REXEC_SCREAM) {
-	char *strbeg = SvPVX(sv);	/* XXXX Assume PV_force() on SCREAM! */
 	I32 p = -1;			/* Internal iterator of scream. */
 	I32 *pp = data ? data->scream_pos : &p;
 
@@ -670,7 +671,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 	/* Even in this situation we may use MBOL flag if strpos is offset
 	   wrt the start of the string. */
 	if (ml_anch && sv && !SvROK(sv)	/* See prev comment on SvROK */
-	    && (strpos + SvCUR(sv) != strend) && strpos[-1] != '\n'
+	    && (strpos != strbeg) && strpos[-1] != '\n'
 	    /* May be due to an implicit anchor of m{.*foo}  */
 	    && !(prog->reganch & ROPT_IMPLICIT))
 	{
@@ -721,7 +722,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 		? s + (prog->minlen? cl_l : 0)
 		: (prog->float_substr ? check_at - start_shift + cl_l
 				      : strend) ;
-	char *startpos = sv && SvPOK(sv) ? strend - SvCUR(sv) : s;
+	char *startpos = strbeg;
 
 	t = s;
 	if (prog->reganch & ROPT_UTF8) {	
diff --git a/t/op/pat.t b/t/op/pat.t
index f009086..f0cb7dc 100755
--- a/t/op/pat.t
+++ b/t/op/pat.t
@@ -4,7 +4,7 @@
 # the format supported by op/regexp.t.  If you want to add a test
 # that does fit that format, add it to op/re_tests, not here.
 
-print "1..223\n";
+print "1..224\n";
 
 BEGIN {
     chdir 't' if -d 't';
@@ -1084,3 +1084,7 @@ print "not " unless "@space2" eq "spc tab";
 print "ok $test\n";
 $test++;
  
+# bugid 20001021.005 - this caused a SEGV
+print "not " unless undef =~ /^([^\/]*)(.*)$/;
+print "ok $test\n";
+$test++;