The regexec.c change of #3606 caused a core dump in fbm_instr()

if its caller re_intuit_start() was entered with strend == strpos
because end_shift ended up as -1.  The patch ain't necessarily
correct but least the core dump is avoided.

p4raw-id: //depot/cfgperl@3671

1 files changed, 2 insertions, 0 deletions

diff --git a/regexec.c b/regexec.c
index 4df60acaa9..e40d1c7ea7 100644
--- a/regexec.c
+++ b/regexec.c
@@ -358,6 +358,8 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     }
 
   restart:
+    if (end_shift < 0)
+	end_shift = 0; /* can happen when strend == strpos */
     if (flags & REXEC_SCREAM) {
 	SV *c = prog->check_substr;
 	char *strbeg = SvPVX(sv);	/* XXXX Assume PV_force() on SCREAM! */