From 8d29cf132caf3de81986179b10746f31123c96b9 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Thu, 19 Dec 2019 08:38:51 +0000
Subject: testcommon: fix run_script for older Perls

Using Perl "open" to dup(2) and save the old handles is required
since "local *STDIN = *STDIN" does not work on old Perls.  Even
worse, this was silently a no-op when tested with Perl 5.24.1 on
Debian 9.x and led to confusing failures in the t/httpd-corner.t
lsof(1) tests when run after t/v2mirror.t from the same worker
process using t/run.perl.
---
 lib/PublicInbox/TestCommon.pm | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

(limited to 'lib/PublicInbox/TestCommon.pm')

diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 85cda031..2828c0d0 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -67,12 +67,27 @@ sub key2script ($) {
 	'blib/script/'.$key;
 }
 
+my @io_mode = ([ *STDIN{IO}, '<&' ], [ *STDOUT{IO}, '>&' ],
+		[ *STDERR{IO}, '>&' ]);
+
 sub _prepare_redirects ($) {
 	my ($fhref) = @_;
-	my @x = ([ \*STDIN, '<&' ], [ \*STDOUT, '>&' ], [ \*STDERR, '>&' ]);
-	for (my $fd = 0; $fd <= $#x; $fd++) {
+	my $orig_io = [];
+	for (my $fd = 0; $fd <= $#io_mode; $fd++) {
 		my $fh = $fhref->[$fd] or next;
-		my ($oldfh, $mode) = @{$x[$fd]};
+		my ($oldfh, $mode) = @{$io_mode[$fd]};
+		open my $orig, $mode, $oldfh or die "$$oldfh $mode stash: $!";
+		$orig_io->[$fd] = $orig;
+		open $oldfh, $mode, $fh or die "$$oldfh $mode redirect: $!";
+	}
+	$orig_io;
+}
+
+sub _undo_redirects ($) {
+	my ($orig_io) = @_;
+	for (my $fd = 0; $fd <= $#io_mode; $fd++) {
+		my $fh = $orig_io->[$fd] or next;
+		my ($oldfh, $mode) = @{$io_mode[$fd]};
 		open $oldfh, $mode, $fh or die "$$oldfh $mode redirect: $!";
 	}
 }
@@ -174,14 +189,14 @@ sub run_script ($;$$) {
 			$r == $pid or die "waitpid: expected $pid, got $r";
 		}
 	} else { # localize and run everything in the same process:
-		local *STDIN = *STDIN;
-		local *STDOUT = *STDOUT;
-		local *STDERR = *STDERR;
+		# note: "local *STDIN = *STDIN;" and so forth did not work in
+		# old versions of perl
 		local %ENV = $env ? (%ENV, %$env) : %ENV;
 		local %SIG = %SIG;
 		local $0 = join(' ', @$cmd);
-		_prepare_redirects($fhref);
+		my $orig_io = _prepare_redirects($fhref);
 		_run_sub($sub, $key, \@argv);
+		_undo_redirects($orig_io);
 	}
 
 	# slurp the redirects back into user-supplied strings
-- 
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