Add `git svn blame' command

This command is identical to `git blame', but it shows SVN revision
numbers instead of git commit hashes.

[ew: support "^initial commit" and minor formatting fixes]

Signed-off-by: Tim Stoakes <tim@stoakes.net>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-svn.txt

@@ -161,6 +161,13 @@ New features:
 +
 Any other arguments are passed directly to `git log'
 
+'blame'::
+       Show what revision and author last modified each line of a file. This is
+       identical to `git blame', but SVN revision numbers are shown instead of git
+       commit hashes.
++
+All arguments are passed directly to `git blame'.
+
 --
 'find-rev'::
 	When given an SVN revision number of the form 'rN', returns the

git-svn.perl

@@ -186,6 +186,9 @@ BEGIN
 		    "Show info about the latest SVN revision
 		     on the current branch",
 		    { 'url' => \$_url, } ],
+	'blame' => [ \&Git::SVN::Log::cmd_blame,
+	            "Show what revision and author last modified each line of a file",
+	            {} ],
 );
 
 my $cmd;
@@ -4448,6 +4451,24 @@ sub cmd_show_log {
 	print commit_log_separator unless $incremental || $oneline;
 }
 
+sub cmd_blame {
+	my $path = shift;
+
+	config_pager();
+	run_pager();
+
+	my ($fh, $ctx) = command_output_pipe('blame', @_, $path);
+	while (my $line = <$fh>) {
+		if ($line =~ /^\^?([[:xdigit:]]+)\s/) {
+			my (undef, $rev, undef) = ::cmt_metadata($1);
+			$rev = sprintf('%-10s', $rev);
+			$line =~ s/^\^?[[:xdigit:]]+(\s)/$rev$1/;
+		}
+		print $line;
+	}
+	command_close_pipe($fh, $ctx);
+}
+
 package Git::SVN::Migration;
 # these version numbers do NOT correspond to actual version numbers
 # of git nor git-svn.  They are just relative.