Merge branch 'jc/disable-push-nego-for-deletion' into next

"git push" that pushes only deletion gave an unnecessary and
harmless error message when push negotiation is configured, which
has been corrected.

* jc/disable-push-nego-for-deletion:
  push: avoid showing false negotiation errors

send-pack.c

@@ -427,17 +427,26 @@ static void get_commons_through_negotiation(const char *url,
  struct child_process child = CHILD_PROCESS_INIT;
  const struct ref *ref;
  int len = the_hash_algo->hexsz + 1; /* hash + NL */
+ int nr_negotiation_tip = 0;
 
  child.git_cmd = 1;
  child.no_stdin = 1;
  child.out = -1;
  strvec_pushl(&child.args, "fetch", "--negotiate-only", NULL);
  for (ref = remote_refs; ref; ref = ref->next) {
- if (!is_null_oid(&ref->new_oid))
- strvec_pushf(&child.args, "--negotiation-tip=%s", oid_to_hex(&ref->new_oid));
+ if (!is_null_oid(&ref->new_oid)) {
+ strvec_pushf(&child.args, "--negotiation-tip=%s",
+ oid_to_hex(&ref->new_oid));
+ nr_negotiation_tip++;
+ }
  }
  strvec_push(&child.args, url);
 
+ if (!nr_negotiation_tip) {
+ child_process_clear(&child);
+ return;
+ }
+
  if (start_command(&child))
  die(_("send-pack: unable to fork off fetch subprocess"));
 

t/t5516-fetch-push.sh

@@ -230,6 +230,16 @@ test_expect_success 'push with negotiation proceeds anyway even if negotiation f
  test_grep "push negotiation failed" err
 '
 
+test_expect_success 'push deletion with negotiation' '
+ mk_empty testrepo &&
+ git push testrepo $the_first_commit:refs/heads/master &&
+ git -c push.negotiate=1 push testrepo \
+ :master $the_first_commit:refs/heads/next 2>errors-2 &&
+ test_grep ! "negotiate-only needs one or " errors-2 &&
+ git -c push.negotiate=1 push testrepo :next 2>errors-1 &&
+ test_grep ! "negotiate-only needs one or " errors-1
+'
+
 test_expect_success 'push with negotiation does not attempt to fetch submodules' '
  mk_empty submodule_upstream &&
  test_commit -C submodule_upstream submodule_commit &&