Add a --dry-run option to git-svn rebase

When working with multiple branches in an svn repository, it can be
useful to verify the svn repository and local tracking branch that will
be used for the rebase operation.

Signed-off-by: Seth Falcon <seth@userprimary.net>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-svn.txt

@@ -365,11 +365,15 @@ Passed directly to git-rebase when using 'dcommit' if a
 -n::
 --dry-run::
 
-This is only used with the 'dcommit' command.
+This can be used with the 'dcommit' and 'rebase' commands.
 
-Print out the series of git arguments that would show
+For 'dcommit', print out the series of git arguments that would show
 which diffs would be committed to SVN.
 
+For 'rebase', display the local branch associated with the upstream svn
+repository associated with the current branch and the URL of svn
+repository that will be fetched from.
+
 --
 
 ADVANCED OPTIONS

git-svn.perl

@@ -177,6 +177,7 @@ my %cmd = (
 			  'strategy|s=s' => \$_strategy,
 			  'local|l' => \$_local,
 			  'fetch-all|all' => \$_fetch_all,
+			  'dry-run|n' => \$_dry_run,
 			  %fc_opts } ],
 	'commit-diff' => [ \&cmd_commit_diff,
 	                   'Commit a diff between two trees',
@@ -557,6 +558,11 @@ sub cmd_rebase {
 		die "Unable to determine upstream SVN information from ",
 		    "working tree history\n";
 	}
+	if ($_dry_run) {
+		print "Remote Branch: " . $gs->refname . "\n";
+		print "SVN URL: " . $url . "\n";
+		return;
+	}
 	if (command(qw/diff-index HEAD --/)) {
 		print STDERR "Cannot rebase with uncommited changes:\n";
 		command_noisy('status');