pack-objects: fix buggy warning about threads

Fix a buggy warning about threads under NO_PTHREADS=YesPlease. Due to
re-using the delta_search_threads variable for both the state of the
"pack.threads" config & the --threads option, setting "pack.threads"
but not supplying --threads would trigger the warning for both
"pack.threads" & --threads.

Solve this bug by resetting the delta_search_threads variable in
git_pack_config(), it might then be set by --threads again and be
subsequently warned about, as the test I'm changing here asserts.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/pack-objects.c

@@ -2472,8 +2472,10 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 			die("invalid number of threads specified (%d)",
 			    delta_search_threads);
 #ifdef NO_PTHREADS
-		if (delta_search_threads != 1)
+		if (delta_search_threads != 1) {
 			warning("no threads support, ignoring %s", k);
+			delta_search_threads = 0;
+		}
 #endif
 		return 0;
 	}

t/t5300-pack-object.sh

@@ -447,7 +447,7 @@ test_expect_success !PTHREADS,C_LOCALE_OUTPUT 'pack-objects --threads=N or pack.
 
 	git -c pack.threads=2 pack-objects --stdout --all </dev/null >/dev/null 2>err &&
 	grep ^warning: err >warnings &&
-	test_must_fail test_line_count = 1 warnings &&
+	test_line_count = 1 warnings &&
 	grep -F "no threads support, ignoring pack.threads" err &&
 
 	git -c pack.threads=2 pack-objects --threads=4 --stdout --all </dev/null >/dev/null 2>err &&