push: respect --no-thin

- From the beginning of push.c in 755225d, 2006-04-29, "thin" option
  was enabled by default but could be turned off with --no-thin.

- Then Shawn changed the default to 0 in favor of saving server
  resources in a4503a1, 2007-09-09. --no-thin worked great.

- One day later, in 9b28851 Daniel extracted some code from push.c to
  create transport.c. He (probably accidentally) flipped the default
  value from 0 to 1 in transport_get().

From then on --no-thin is effectively no-op because git-push still
expects the default value to be false and only calls
transport_set_option() when "thin" variable in push.c is true (which
is unnecessary). Correct the code to respect --no-thin by calling
transport_set_option() in both cases.

receive-pack learns about --reject-thin-pack-for-testing option,
which only is for testing purposes, hence no document update.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5516-fetch-push.sh

@@ -1172,4 +1172,21 @@ test_expect_success 'push --follow-tag only pushes relevant tags' '
 	test_cmp expect actual
 '
 
+test_expect_success 'push --no-thin must produce non-thin pack' '
+	cat >>path1 <<\EOF &&
+keep base version of path1 big enough, compared to the new changes
+later, in order to pass size heuristics in
+builtin/pack-objects.c:try_delta()
+EOF
+	git commit -am initial &&
+	git init no-thin &&
+	git --git-dir=no-thin/.git config receive.unpacklimit 0 &&
+	git push no-thin/.git refs/heads/master:refs/heads/foo &&
+	echo modified >> path1 &&
+	git commit -am modified &&
+	git repack -adf &&
+	rcvpck="git receive-pack --reject-thin-pack-for-testing" &&
+	git push --no-thin --receive-pack="$rcvpck" no-thin/.git refs/heads/master:refs/heads/foo
+'
+
 test_done