t0014: factor out choice of deprecated commands

We have a few tests related to aliasing deprecated commands which use
"whatchanged" and "pack-redundant", as these are the only two deprecated
commands we have. Let's pull those names into variables so that we can
refactor the tests without relying on the specific names.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0014-alias.sh

@@ -27,17 +27,20 @@ test_expect_success 'looping aliases - internal execution' '
 	test_grep "^fatal: alias loop detected: expansion of" output
 '
 
+deprecated1=whatchanged
+deprecated2=pack-redundant
+
 test_expect_success 'looping aliases - deprecated builtins' '
-	test_config alias.whatchanged pack-redundant &&
-	test_config alias.pack-redundant whatchanged &&
+	test_config alias.$deprecated1 $deprecated2 &&
+	test_config alias.$deprecated2 $deprecated1 &&
 	cat >expect <<-EOF &&
-	${SQ}whatchanged${SQ} is aliased to ${SQ}pack-redundant${SQ}
-	${SQ}pack-redundant${SQ} is aliased to ${SQ}whatchanged${SQ}
-	fatal: alias loop detected: expansion of ${SQ}whatchanged${SQ} does not terminate:
-	  whatchanged <==
-	  pack-redundant ==>
+	${SQ}$deprecated1${SQ} is aliased to ${SQ}$deprecated2${SQ}
+	${SQ}$deprecated2${SQ} is aliased to ${SQ}$deprecated1${SQ}
+	fatal: alias loop detected: expansion of ${SQ}$deprecated1${SQ} does not terminate:
+	  $deprecated1 <==
+	  $deprecated2 ==>
 	EOF
-	test_must_fail git whatchanged -h 2>actual &&
+	test_must_fail git $deprecated1 -h 2>actual &&
 	test_cmp expect actual
 '
 
@@ -90,8 +93,8 @@ test_expect_success 'can alias-shadow via two deprecated builtins' '
 	# some git(1) commands will fail... (see above)
 	test_might_fail git status -h >expect &&
 	test_file_not_empty expect &&
-	test_might_fail git -c alias.whatchanged=pack-redundant \
-		-c alias.pack-redundant=status whatchanged -h >actual &&
+	test_might_fail git -c alias.$deprecated1=$deprecated2 \
+		-c alias.$deprecated2=status $deprecated1 -h >actual &&
 	test_cmp expect actual
 '