add -i: return from list_and_choose if there is no candidate

The list_and_choose() helper is given a prompt and a list, asks the
user to make selection from the list, and then returns a list of
items chosen.  Even when it is given an empty list as the original
candidate set to choose from, it gave a prompt to the user, who can
only say "I am done choosing".

Return an empty result when the input is an empty list without
bothering the user.  The existing caller must already have a logic
to say "Nothing to do" or an equivalent when the returned list is
empty (i.e. the user chose to select nothing) if it is necessary, so
no change to the callers is necessary.

This fixes the case where "add untracked" is asked in "git add -i"
and there is no untracked files in the working tree.  We used to give
an empty list of files to choose from with a prompt, but with this
change, we no longer do.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 1fadd69f8809f91337a27b98f244a3cf7183b23f..f35b3e61527d3e1d6ec2b40b085e456e96b1c294 100755 (executable)
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -515,6 +515,9 @@ sub error_msg {
 sub list_and_choose {
        my ($opts, @stuff) = @_;
        my (@chosen, @return);
+       if (!@stuff) {
+           return @return;
+       }
        my $i;
        my @prefixes = find_unique_prefixes(@stuff) unless $opts->{LIST_ONLY};
 
@@ -725,6 +728,8 @@ sub add_untracked_cmd {
        if (@add) {
                system(qw(git update-index --add --), @add);
                say_n_paths('added', @add);
+       } else {
+               print "No untracked files.\n";
        }
        print "\n";
 }