From cb65aada4214c7ba701e2ea46ba4a17dc12a4025 Mon Sep 17 00:00:00 2001
From: David Mitchell <davem@iabyn.com>
Date: Fri, 26 Feb 2016 16:40:30 +0000
Subject: [PATCH] Make Test-Block work with perl 5.23.8+

In 5.23.8, the order of steps that perl takes when leaving a scope has
changed. In particular, destructors are now called *before* PL_curcop
is restored and before the context is popped from the stack.

The net effect of this is that caller() called from a destructor called
while exiting a scope will see the last line of the exiting scope rather
than its first line, and may see STOREs still in the call stack that
were triggered by undoing a locations of a tied variable, that themselves
trigger destructors.


Bug: https://rt.cpan.org/Public/Bug/Display.html?id=112462
Bug-Debian: https://bugs.debian.org/825670

---
 Test-Block-0.13/lib/Test/Block.pm | 16 ++++++++++++++++
 Test-Block-0.13/t/block.t         | 10 +++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lib/Test/Block.pm b/lib/Test/Block.pm
index 1598ea7..3e1b029 100644
--- a/lib/Test/Block.pm
+++ b/lib/Test/Block.pm
@@ -59,6 +59,22 @@ sub DESTROY {
     my $name = $self->{name};
     my $tests_ran = _tests_run_in_block($self);
     $name = "'$name'" unless looks_like_number( $name );
+
+    # In perl 5.23.7 and earlier, the call stack at this point looks like:
+    #
+    #     Test::Block::DESTROY(...)     called at test_script line NNN
+    #     eval {...}                    called at test_script line NNN
+    #
+    # in perl 5.23.8 and later, like:
+    #
+    #     Test::Block::DESTROY(...)     called at Tie/Scalar.pm line 157
+    #     eval {...}                    called at Tie/Scalar.pm line 157
+    #     Tie::StdScalar::STORE(...)    called at Test/Block.pm line 96
+    #     Test::Block::Plan::STORE(...) called at test_script line NNN
+    #
+    local $Test::Builder::Level =
+        $Test::Builder::Level + ($] >= 5.023008 ? 3 : 0);
+
     $Test_builder->ok(
         0, 
         "block $name expected $expected test(s) and ran $tests_ran"
diff --git a/t/block.t b/t/block.t
index fbf8469..4a9f814 100644
--- a/t/block.t
+++ b/t/block.t
@@ -4,6 +4,10 @@ use Test::Builder::Tester tests => 6;
 use Test::More;
 use Test::Block;
 
+# in perl 5.23.8 and later, caller() in a destructor called while
+# exiting a block shows the last line of the block, not the first
+my $lastl = $] >= 5.023008;
+
 test_out('ok 1');
 {
 	my $block = Test::Block->plan(1);
@@ -14,7 +18,7 @@ test_test("count okay");
 
 test_out('ok 1');
 test_out('not ok 2 - block 2 expected 2 test(s) and ran 1');
-test_fail(+2);
+test_fail($lastl ? +3 : +2);
 {
 	my $block = Test::Block->plan(2);
 	ok(1);
@@ -25,7 +29,7 @@ test_test("too few tests");
 test_out('ok 1');
 test_out('ok 2');
 test_out('not ok 3 - block 3 expected 1 test(s) and ran 2');
-test_fail(+2);
+test_fail($lastl ? +4 : +2);
 {
 	my $block = Test::Block->plan(1);
 	ok(1);
@@ -57,7 +61,7 @@ test_test("nested blocks");
 
 test_out('ok 1');
 test_out("not ok 2 - block 'foo' expected 2 test(s) and ran 1");
-test_fail(+2);
+test_fail($lastl ? +3 : +2);
 {
 	my $block = Test::Block->plan(foo => 2);
 	ok(1);
-- 
2.4.3