git-svn: write memoized data explicitly to avoid Storable bug

Apparently using the Storable module during global destruction is
unsafe - there is a bug which can cause segmentation faults:

  http://rt.cpan.org/Public/Bug/Display.html?id=36087
  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=482355

The persistent memoization support introduced in commit 8bff7c538
relied on global destruction to write cached data, which was leading
to segfaults in some Perl configurations.  Calling Memoize::unmemoize
in the END block forces the cache writeout to be performed earlier,
thus avoiding the bug.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Acked-by: Eric Wong <normalperson@yhbt.net>

git-svn.perl

@@ -3169,6 +3169,22 @@ sub has_no_changes {
 			LIST_CACHE => 'FAULT',
 		;
 	}
+
+	sub unmemoize_svn_mergeinfo_functions {
+		return if not $memoized;
+		$memoized = 0;
+
+		Memoize::unmemoize 'lookup_svn_merge';
+		Memoize::unmemoize 'check_cherry_pick';
+		Memoize::unmemoize 'has_no_changes';
+	}
+}
+
+END {
+	# Force cache writeout explicitly instead of waiting for
+	# global destruction to avoid segfault in Storable:
+	# http://rt.cpan.org/Public/Bug/Display.html?id=36087
+	unmemoize_svn_mergeinfo_functions();
 }
 
 sub parents_exclude {