Re: git-svn: SVK merge commits can have >2 parents

[Alex Vandiver <alex@chmrr.net>]

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At Sun Nov 29 02:28:39 -0500 2009, Alex Vandiver wrote:
> While converting a mildly complicated svn repository that was managed
> with SVK, I ran across the following oddness.  `svk smerge` can only
> merge between _two_ branches at once -- however, the way that svk
> merge detection works, you can end up with erroneous extra parents
> from long-dead branches.

Upon a little more inspection, I now understand that the rev-parse
lines in find_extra_svk_parents are attempting to deal with this exact
circumstance -- but they fail to properly sort the merge tickets
first, which leads to this incorrect behavior.  Armed with this
understanding, I'm more confident in the attached updated patch.  I
assume, however, that the logic allows for more than one extra parent
only because such an occurrance could be constructed by hand-editing
svk:merge, because AFAIK svk's command-line tools should be able to
construct such a circumstance.
 - Alex
-- 
Networking -- only one letter away from not working

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From 4d30e57e5da7c2e880908bc742cf80990d6f9f5d Mon Sep 17 00:00:00 2001
From: Alex Vandiver <alex@chmrr.net>
Date: Sun, 29 Nov 2009 02:20:21 -0500
Subject: [PATCH] git-svn: sort svk merge tickets to account for minimal parents

When merging branches based on svk:merge properties, a single merge
can have updated or added multiple svk:merge lines.  Attempt to
include the minimal set of parents by sorting the merge properties in
order of revision, highest to lowest.

Signed-off-by: Alex Vandiver <alex@chmrr.net>
---
 git-svn.perl |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/git-svn.perl b/git-svn.perl
index 957d44e..51f03ad 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -2940,10 +2940,14 @@ sub find_extra_svk_parents {
 			if ( my $commit = $gs->rev_map_get($rev, $uuid) ) {
 				# wahey!  we found it, but it might be
 				# an old one (!)
-				push @known_parents, $commit;
+				push @known_parents, [ $rev, $commit ];
 			}
 		}
 	}
+	# Ordering matters; highest-numbered commit merge tickets
+	# first, as they may account for later merge ticket additions
+	# or changes.
+	@known_parents = map {$_->[1]} sort {$b->[0] <=> $a->[0]} @known_parents;
 	for my $parent ( @known_parents ) {
 		my @cmd = ('rev-list', $parent, map { "^$_" } @$parents );
 		my ($msg_fh, $ctx) = command_output_pipe(@cmd);
-- 
1.6.6.rc0.254.g7352d