[PATCH] git-svn: control destruction order to avoid segfault

From: Eric Wong <e@80x24.org>
Date: Jan 29, 2018, 23:16 UTC
Message-ID: <20180129231653.GA22834@starla>
In-Reply-To: <20180129184345.GI1427@zaya.teonanacatl.net>

Todd Zullinger <tmz@pobox.com> wrote:

> I'm running the tests with and without your patch as well.
> So far I've run t9128 300 times with the patch and no
> failures.  Without it, it's failed 3 times in only a few
> dozen runs.  That's promising.

Thanks for confirming it works on other systems. Pull request and patch below:

The following changes since commit 5be1f00a9a701532232f57958efab4be8c959a29:

  First batch after 2.16 (2018-01-23 13:21:10 -0800)

are available in the Git repository at:

  git://bogomips.org/git-svn.git svn-branch-segfault

for you to fetch changes up to 2784b8d68faca823489949cbc69ead2f296cfc07:

  git-svn: control destruction order to avoid segfault (2018-01-29 23:12:00 +0000)

----------------------------------------------------------------
Eric Wong (1):
      git-svn: control destruction order to avoid segfault

 git-svn.perl | 5 +++++
 1 file changed, 5 insertions(+)

---------8<---------
Subject: [PATCH] git-svn: control destruction order to avoid segfault

It seems necessary to control destruction ordering to avoid a segfault with SVN 1.9.5 when using "git svn branch". I've also reported the problem against libsvn-perl to Debian [Bug #888791], but releasing the SVN::Client instance can be beneficial anyways to save memory.

ref: https://bugs.debian.org/888791
Tested-by: Todd Zullinger <tmz@pobox.com>
Reported-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Eric Wong <e@80x24.org>
---
 git-svn.perl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/git-svn.perl b/git-svn.perl
index 76a75d0b3d..a6b6c3e40c 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -1200,6 +1200,11 @@ sub cmd_branch {
 	$ctx->copy($src, $rev, $dst)
 		unless $_dry_run;
 
+	# Release resources held by ctx before creating another SVN::Ra
+	# so destruction is orderly.  This seems necessary with SVN 1.9.5
+	# to avoid segfaults.
+	$ctx = undef;
+
 	$gs->fetch_all;
 }

-- 
EW