fix RE brokenness on refs/overloaded things (from Ilya Zakharevich)

p4raw-id: //depot/perl@5931

3 files changed, 24 insertions, 4 deletions

diff --git a/pp_hot.c b/pp_hot.c
index c888ea5e71..5db5eab6f7 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1021,7 +1021,8 @@ play_it_again:
 	     && !PL_sawampersand 
 	     && ((rx->reganch & ROPT_NOSCAN)
 		 || !((rx->reganch & RE_INTUIT_TAIL)
-		      && (r_flags & REXEC_SCREAM))))
+		      && (r_flags & REXEC_SCREAM)))
+	     && !SvROK(TARG))	/* Cannot trust since INTUIT cannot guess ^ */
 	    goto yup;
     }
     if (CALLREGEXEC(aTHX_ rx, s, strend, truebase, minmatch, TARG, NULL, r_flags))
diff --git a/regexec.c b/regexec.c
index 3b6d8577a7..8f5278c254 100644
--- a/regexec.c
+++ b/regexec.c
@@ -346,7 +346,9 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 	    I32 slen;
 
 	    if ( !(prog->reganch & ROPT_ANCH_GPOS) /* Checked by the caller */
-		 && (sv && (strpos + SvCUR(sv) != strend)) ) {
+		 /* SvCUR is not set on references: SvRV and SvPVX overlap */
+		 && sv && !SvROK(sv)
+		 && (strpos + SvCUR(sv) != strend)) {
 		DEBUG_r(PerlIO_printf(Perl_debug_log, "Not at start...\n"));
 		goto fail;
 	    }
@@ -638,7 +640,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
       try_at_start:
 	/* Even in this situation we may use MBOL flag if strpos is offset
 	   wrt the start of the string. */
-	if (ml_anch && sv
+	if (ml_anch && sv && !SvROK(sv)	/* See prev comment on SvROK */
 	    && (strpos + SvCUR(sv) != strend) && strpos[-1] != '\n'
 	    /* May be due to an implicit anchor of m{.*foo}  */
 	    && !(prog->reganch & ROPT_IMPLICIT))
diff --git a/t/op/pat.t b/t/op/pat.t
index 188a3a3b13..e00328c91f 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..211\n";
+print "1..213\n";
 
 BEGIN {
     chdir 't' if -d 't';
@@ -995,3 +995,20 @@ $test++;
 "\n\n" =~ /\n+ $ \n/x or print "not ";
 print "ok $test\n";
 $test++;
+
+[] =~ /^ARRAY/ or print "# [] \nnot ";
+print "ok $test\n";
+$test++;
+
+eval << 'EOE';
+{
+ package S;
+ use overload '""' => sub { 'Object S' };
+ sub new { bless [] }
+}
+$a = 'S'->new;
+EOE
+
+$a and $a =~ /^Object\sS/ or print "# '$a' \nnot ";
+print "ok $test\n";
+$test++;