Only update clean git checkouts

Ticket: https://progress.opensuse.org/issues/165066

lib/OpenQA/Task/Git/Clone.pm

@@ -91,6 +91,12 @@ sub _git_reset_hard ($path, $branch) {
     die "Failed to reset to 'origin/$branch': $r->{stderr}" unless $r->{status};
 }
 
+sub _git_is_workdir_clean ($path) {
+    my $r = run_cmd_with_log_return_error(['git', '-C', $path, 'diff-index', 'HEAD', '--exit-code']);
+    return $r->{status};
+}
+
+
 sub _git_clone ($job, $ctx, $path, $url) {
     $ctx->debug(qq{Updating $path to $url});
     $url = Mojo::URL->new($url);
@@ -112,10 +118,15 @@ sub _git_clone ($job, $ctx, $path, $url) {
         $ctx->debug(qq{Remote default branch $remote_default});
     }
 
-    my $current_branch = _get_current_branch($path);
-    # updating default branch (including checkout)
-    _git_fetch($path, $requested_branch);
-    _git_reset_hard($path, $requested_branch) if ($requested_branch eq $current_branch);
+    if (_git_is_workdir_clean($path)) {
+        my $current_branch = _get_current_branch($path);
+        # updating default branch (including checkout)
+        _git_fetch($path, $requested_branch);
+        _git_reset_hard($path, $requested_branch) if ($requested_branch eq $current_branch);
+    }
+    else {
+        $ctx->warn("NOT updating dirty git checkout at $path");
+    }
 }
 
 1;