push test: use test_config when appropriate

Configuration from test_config does not last beyond the end of the
current test assertion, making each test easier to think about in
isolation.

This changes the meaning of some of the tests.  For example, currently
"push with insteadOf" passes even if the line setting
"url.$TRASH.pushInsteadOf" is dropped because an url.$TRASH.insteadOf
setting leaks in from a previous test.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5516-fetch-push.sh

@@ -203,7 +203,7 @@ test_expect_success 'push with wildcard' '
 test_expect_success 'push with insteadOf' '
 	mk_empty &&
 	TRASH="$(pwd)/" &&
-	git config "url.$TRASH.insteadOf" trash/ &&
+	test_config "url.$TRASH.insteadOf" trash/ &&
 	git push trash/testrepo refs/heads/master:refs/remotes/origin/master &&
 	(
 		cd testrepo &&
@@ -217,7 +217,7 @@ test_expect_success 'push with insteadOf' '
 test_expect_success 'push with pushInsteadOf' '
 	mk_empty &&
 	TRASH="$(pwd)/" &&
-	git config "url.$TRASH.pushInsteadOf" trash/ &&
+	test_config "url.$TRASH.pushInsteadOf" trash/ &&
 	git push trash/testrepo refs/heads/master:refs/remotes/origin/master &&
 	(
 		cd testrepo &&
@@ -231,9 +231,9 @@ test_expect_success 'push with pushInsteadOf' '
 test_expect_success 'push with pushInsteadOf and explicit pushurl (pushInsteadOf should not rewrite)' '
 	mk_empty &&
 	TRASH="$(pwd)/" &&
-	git config "url.trash2/.pushInsteadOf" trash/ &&
-	git config remote.r.url trash/wrong &&
-	git config remote.r.pushurl "$TRASH/testrepo" &&
+	test_config "url.trash2/.pushInsteadOf" trash/ &&
+	test_config remote.r.url trash/wrong &&
+	test_config remote.r.pushurl "$TRASH/testrepo" &&
 	git push r refs/heads/master:refs/remotes/origin/master &&
 	(
 		cd testrepo &&
@@ -489,31 +489,24 @@ test_expect_success 'push with config remote.*.push = HEAD' '
 		git checkout local &&
 		git reset --hard $the_first_commit
 	) &&
-	git config remote.there.url testrepo &&
-	git config remote.there.push HEAD &&
-	git config branch.master.remote there &&
+	test_config remote.there.url testrepo &&
+	test_config remote.there.push HEAD &&
+	test_config branch.master.remote there &&
 	git push &&
 	check_push_result $the_commit heads/master &&
 	check_push_result $the_first_commit heads/local
 '
 
-# clean up the cruft left with the previous one
-git config --remove-section remote.there
-git config --remove-section branch.master
-
 test_expect_success 'push with config remote.*.pushurl' '
 
 	mk_test heads/master &&
 	git checkout master &&
-	git config remote.there.url test2repo &&
-	git config remote.there.pushurl testrepo &&
+	test_config remote.there.url test2repo &&
+	test_config remote.there.pushurl testrepo &&
 	git push there &&
 	check_push_result $the_commit heads/master
 '
 
-# clean up the cruft left with the previous one
-git config --remove-section remote.there
-
 test_expect_success 'push with dry-run' '
 
 	mk_test heads/master &&