[perl #54956] crash on binary-or lvalue operation on qr//

This fixes the following problem:

  -e 'my $re = qr/x/; $re |= "y"'
  assert failure under 5.10.0, 10-maint, bleed, but not 5.8.8

1 files changed, 7 insertions, 1 deletions

diff --git a/doop.c b/doop.c
index cd9b3b4f17..c08f84e847 100644
--- a/doop.c
+++ b/doop.c
@@ -1231,7 +1231,13 @@ Perl_do_vop(pTHX_ I32 optype, SV *sv, SV *left, SV *right)
 
     if (sv != left || (optype != OP_BIT_AND && !SvOK(sv) && !SvGMAGICAL(sv)))
 	sv_setpvs(sv, "");	/* avoid undef warning on |= and ^= */
-    lsave = lc = SvPV_nomg_const(left, leftlen);
+    if (sv == left) {
+	lsave = lc = SvPV_force_nomg(left, leftlen);
+    }
+    else {
+	lsave = lc = SvPV_nomg_const(left, leftlen);
+	SvPV_force_nomg_nolen(sv);
+    }
     rsave = rc = SvPV_nomg_const(right, rightlen);
 
     /* This need to come after SvPV to ensure that string overloading has