+
+sub check_upgrade_needed {
+ my $old = eval {
+ my $pid = open my $child, '-|';
+ defined $pid or croak $!;
+ if ($pid == 0) {
+ close STDERR;
+ exec('git-rev-parse',"$GIT_SVN-HEAD") or croak $?;
+ }
+ my @ret = (<$child>);
+ close $child or croak $?;
+ die $? if $?; # just in case close didn't error out
+ return wantarray ? @ret : join('',@ret);
+ };
+ return unless $old;
+ my $head = eval { safe_qx('git-rev-parse',"refs/remotes/$GIT_SVN") };
+ if ($@ || !$head) {
+ print STDERR "Please run: $0 rebuild --upgrade\n";
+ exit 1;
+ }
+}
+
+# fills %tree_map with a reverse mapping of trees to commits. Useful
+# for finding parents to commit on.
+sub map_tree_joins {
+ foreach my $br (@_branch_from) {
+ my $pid = open my $pipe, '-|';
+ defined $pid or croak $!;
+ if ($pid == 0) {
+ exec(qw(git-rev-list --pretty=raw), $br) or croak $?;
+ }
+ while (<$pipe>) {
+ if (/^commit ($sha1)$/o) {
+ my $commit = $1;
+ my ($tree) = (<$pipe> =~ /^tree ($sha1)$/o);
+ unless (defined $tree) {
+ die "Failed to parse commit $commit\n";
+ }
+ push @{$tree_map{$tree}}, $commit;
+ }
+ }
+ close $pipe or croak $?;
+ }
+}
+
+# '<svn username> = real-name <email address>' mapping based on git-svnimport:
+sub load_authors {
+ open my $authors, '<', $_authors or die "Can't open $_authors $!\n";
+ while (<$authors>) {
+ chomp;
+ next unless /^(\S+?)\s*=\s*(.+?)\s*<(.+)>\s*$/;
+ my ($user, $name, $email) = ($1, $2, $3);
+ $users{$user} = [$name, $email];
+ }
+ close $authors or croak $!;
+}
+