From: Rafael Garcia-Suarez <rgarciasuarez@gmail.com>
Date: Wed, 30 Nov 2005 09:53:11 +0000 (+0000)
Subject: Revert change #22520 (optimise away my $foo = undef and similar
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=7c8a3dfd3bf64e6ea427f38183b879af54fe8f18;p=p5sagit%2Fp5-mst-13.2.git

Revert change #22520 (optimise away my $foo = undef and similar
constructs), in order to fix bug perl #37776
p4raw-link: @22520 on //depot/perl: b9d46b3942a9a8cce9cbca1e08f61ac23083a740

p4raw-id: //depot/perl@26226
---

diff --git a/op.c b/op.c
index aeedab9..6e37131 100644
--- a/op.c
+++ b/op.c
@@ -3300,15 +3300,6 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
 	    /* Result of assignment is always 1 (or we'd be dead already) */
 	    return newSVOP(OP_CONST, 0, newSViv(1));
 	}
-	/* optimise C<my @x = ()> to C<my @x>, and likewise for hashes */
-	if ((left->op_type == OP_PADAV || left->op_type == OP_PADHV)
-		&& right->op_type == OP_STUB
-		&& (left->op_private & OPpLVAL_INTRO))
-	{
-	    op_free(right);
-	    left->op_flags &= ~(OPf_REF|OPf_SPECIAL);
-	    return left;
-	}
 	curop = list(force_list(left));
 	o = newBINOP(OP_AASSIGN, flags, list(force_list(right)), curop);
 	o->op_private = (U8)(0 | (flags >> 8));
@@ -5802,19 +5793,6 @@ Perl_ck_sassign(pTHX_ OP *o)
 	    return kid;
 	}
     }
-    /* optimise C<my $x = undef> to C<my $x> */
-    if (kid->op_type == OP_UNDEF) {
-	OP * const kkid = kid->op_sibling;
-	if (kkid && kkid->op_type == OP_PADSV
-		&& (kkid->op_private & OPpLVAL_INTRO))
-	{
-	    cLISTOPo->op_first = NULL;
-	    kid->op_sibling = NULL;
-	    op_free(o);
-	    op_free(kid);
-	    return kkid;
-	}
-    }
     return o;
 }
 
diff --git a/t/op/my.t b/t/op/my.t
index d219f80..6a477db 100755
--- a/t/op/my.t
+++ b/t/op/my.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..34\n";
+print "1..36\n";
 
 sub foo {
     my($a, $b) = @_;
@@ -120,3 +120,13 @@ eval { foo3(); foo3(); };
 print "not " if $@;
 print "ok 34\n";
 
+# my $foo = undef should always assign [perl #37776]
+{
+    my $count = 35;
+    loop:
+    my $test = undef;
+    print "not " if defined $test;
+    print "ok $count\n";
+    $test = 42;
+    goto loop if ++$count < 37;
+}