+sub lookup_svn_merge {
+ my $uuid = shift;
+ my $url = shift;
+ my $merge = shift;
+
+ my ($source, $revs) = split ":", $merge;
+ my $path = $source;
+ $path =~ s{^/}{};
+ my $gs = Git::SVN->find_by_url($url.$source, $url, $path);
+ if ( !$gs ) {
+ warn "Couldn't find revmap for $url$source\n";
+ return;
+ }
+ my @ranges = split ",", $revs;
+ my ($tip, $tip_commit);
+ my @merged_commit_ranges;
+ # find the tip
+ for my $range ( @ranges ) {
+ my ($bottom, $top) = split "-", $range;
+ $top ||= $bottom;
+ my $bottom_commit = $gs->find_rev_after( $bottom, 1, $top );
+ my $top_commit = $gs->find_rev_before( $top, 1, $bottom );
+
+ unless ($top_commit and $bottom_commit) {
+ warn "W:unknown path/rev in svn:mergeinfo "
+ ."dirprop: $source:$range\n";
+ next;
+ }
+
+ push @merged_commit_ranges,
+ "$bottom_commit^..$top_commit";
+
+ if ( !defined $tip or $top > $tip ) {
+ $tip = $top;
+ $tip_commit = $top_commit;
+ }
+ }
+ return ($tip_commit, @merged_commit_ranges);
+}
+
+sub _rev_list {
+ my ($msg_fh, $ctx) = command_output_pipe(
+ "rev-list", @_,
+ );
+ my @rv;
+ while ( <$msg_fh> ) {
+ chomp;
+ push @rv, $_;
+ }
+ command_close_pipe($msg_fh, $ctx);
+ @rv;
+}
+
+sub check_cherry_pick {
+ my $base = shift;
+ my $tip = shift;
+ my @ranges = @_;
+ my %commits = map { $_ => 1 }
+ _rev_list("--no-merges", $tip, "--not", $base);
+ for my $range ( @ranges ) {
+ delete @commits{_rev_list($range)};
+ }
+ return (keys %commits);
+}
+
+BEGIN {
+ memoize 'lookup_svn_merge';
+ memoize 'check_cherry_pick';
+}
+
+sub parents_exclude {
+ my $parents = shift;
+ my @commits = @_;
+ return unless @commits;
+
+ my @excluded;
+ my $excluded;
+ do {
+ my @cmd = ('rev-list', "-1", @commits, "--not", @$parents );
+ $excluded = command_oneline(@cmd);
+ if ( $excluded ) {
+ my @new;
+ my $found;
+ for my $commit ( @commits ) {
+ if ( $commit eq $excluded ) {
+ push @excluded, $commit;
+ $found++;
+ last;
+ }
+ else {
+ push @new, $commit;
+ }
+ }
+ die "saw commit '$excluded' in rev-list output, "
+ ."but we didn't ask for that commit (wanted: @commits --not @$parents)"
+ unless $found;
+ @commits = @new;
+ }
+ }
+ while ($excluded and @commits);
+
+ return @excluded;
+}
+
+