1 files changed, 13 insertions, 0 deletions
diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index a4ec377..7da60f6 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -51,6 +51,7 @@ BEGIN {
                       git_rev_parse git_cat_file
 		      git_get_ref git_get_symref git_for_each_ref
                       git_for_each_tag_referring is_fast_fwd
+		      git_check_unmodified
                       $package_re $component_re $deliberately_re
 		      $distro_re $versiontag_re $series_filename_re
 		      $extra_orig_namepart_re
@@ -443,6 +444,18 @@ sub git_for_each_tag_referring ($$) {
     });
 }
 
+sub git_check_unmodified () {
+    my @cmd = qw(git diff --quiet HEAD);
+    debugcmd "+",@cmd;
+    $!=0; $?=-1; system @cmd;
+    return if !$?;
+    if ($?==256) {
+	fail "working tree is dirty (does not match HEAD)";
+    } else {
+	failedcmd @cmd;
+    }
+}
+
 sub is_fast_fwd ($$) {
     my ($ancestor,$child) = @_;
     my @cmd = (qw(git merge-base), $ancestor, $child);