From 3c157b3cf0631c69ffa5aa2d55b9199bf93b22a9 Mon Sep 17 00:00:00 2001
From: Zefram <zefram@fysh.org>
Date: Mon, 23 Jan 2017 02:25:50 +0000
Subject: [PATCH] permit goto at top level of multicalled sub

A multicalled sub is reckoned to be a pseudo block, out of which it is
not permissible to goto.  However, the test for a pseudo block was being
applied too early, preventing not just escape from a multicalled sub but
also a goto at the top level within the sub.  This is a bug similar, but
not identical, to [perl #113938].  Now the test is deferred, permitting
goto at the sub's top level but still forbidding goto out of it.
---
 pp_ctl.c    | 11 ++++++-----
 t/op/goto.t | 11 ++++++++++-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/pp_ctl.c b/pp_ctl.c
index 2ced82d..f48f301 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -2946,6 +2946,7 @@ PP(pp_goto)
 	OP *gotoprobe = NULL;
 	bool leaving_eval = FALSE;
 	bool in_block = FALSE;
+	bool pseudo_block = FALSE;
 	PERL_CONTEXT *last_eval_cx = NULL;
 
 	/* find label */
@@ -2984,11 +2985,9 @@ PP(pp_goto)
 		    gotoprobe = PL_main_root;
 		break;
 	    case CXt_SUB:
-		if (CvDEPTH(cx->blk_sub.cv) && !CxMULTICALL(cx)) {
-		    gotoprobe = CvROOT(cx->blk_sub.cv);
-		    break;
-		}
-		/* FALLTHROUGH */
+		gotoprobe = CvROOT(cx->blk_sub.cv);
+		pseudo_block = cBOOL(CxMULTICALL(cx));
+		break;
 	    case CXt_FORMAT:
 	    case CXt_NULL:
 		DIE(aTHX_ "Can't \"goto\" out of a pseudo block");
@@ -3017,6 +3016,8 @@ PP(pp_goto)
 			break;
 		}
 	    }
+	    if (pseudo_block)
+		DIE(aTHX_ "Can't \"goto\" out of a pseudo block");
 	    PL_lastgotoprobe = gotoprobe;
 	}
 	if (!retop)
diff --git a/t/op/goto.t b/t/op/goto.t
index 05f1573..f2f2a25 100644
--- a/t/op/goto.t
+++ b/t/op/goto.t
@@ -10,7 +10,7 @@ BEGIN {
 
 use warnings;
 use strict;
-plan tests => 99;
+plan tests => 100;
 our $TODO;
 
 my $deprecated = 0;
@@ -801,3 +801,12 @@ TODO: {
   }
 EOC
 }
+
+sub revnumcmp ($$) {
+  goto FOO;
+  die;
+  FOO:
+  return $_[1] <=> $_[0];
+}
+is eval { join(":", sort revnumcmp (9,5,1,3,7)) }, "9:7:5:3:1",
+  "can goto at top level of multicalled sub";
-- 
1.8.3.1