git svn: fix dcommit to work with touched files

The dcommit command fails if an otherwise unmodified file has
been touched in the working directory:

    Cannot dcommit with a dirty index.  Commit your changes
    first, or stash them with `git stash'.

This happens because "git diff-index" reports a difference
between the index and the filesystem:

    :100644 100644 d00491...... 000000...... M      file

The fix is to run "git update-index --refresh" before
"git diff-index" as is done in git-rebase and
git-rebase--interactive before "git diff-files".

This changes dcommit to display a list of modified files before
exiting.

Also add a similar test case for "git svn rebase".

[ew: rearranged commit message subject]
Signed-off-by: NDavid D. Kilzer <ddkilzer@kilzer.net>
Acked-by: NEric Wong <normalperson@yhbt.net>

git-svn.perl

@@ -494,6 +494,7 @@ sub cmd_set_tree {
 
 sub cmd_dcommit {
 	my $head = shift;
+	command_noisy(qw/update-index --refresh/);
 	git_cmd_try { command_oneline(qw/diff-index --quiet HEAD/) }
 		'Cannot dcommit with a dirty index.  Commit your changes first, '
 		. "or stash them with `git stash'.\n";

t/t9100-git-svn-basic.sh

@@ -271,6 +271,17 @@ test_expect_success 'able to dcommit to a subdirectory' "
 	test -z \"\`git diff refs/heads/my-bar refs/remotes/bar\`\"
 	"
 
+test_expect_success 'dcommit should not fail with a touched file' '
+	test_commit "commit-new-file-foo2" foo2 &&
+	test-chmtime =-60 foo &&
+	git svn dcommit
+'
+
+test_expect_success 'rebase should not fail with a touched file' '
+	test-chmtime =-60 foo &&
+	git svn rebase
+'
+
 test_expect_success 'able to set-tree to a subdirectory' "
 	echo cba > d &&
 	git update-index d &&