t3030: use test_ln_s_add to remove SYMLINKS prerequisite

The test cases include many corner-cases of merge-recursive's behavior,
some of them involve type changes and symbolic links. All cases, including
those that are protected by SYMLINKS check only whether the result of
merge-recursive is correctly stored in the database and the index; the
file system is not investigated. Use test_ln_s_add to enter a symbolic
link in the index in the test setup and run the tests without the
SYMLINKS prerequisite.

Notice that one test that has the SYMLINKS protection removed is an
expect_failure. There is a possibility that the test fails differently
depending on whether SYMLINKS is present or not; but this is not the case
presently.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3030-merge-recursive.sh

@@ -25,10 +25,7 @@ test_expect_success 'setup 1' '
 	git branch submod &&
 	git branch copy &&
 	git branch rename &&
-	if test_have_prereq SYMLINKS
-	then
-		git branch rename-ln
-	fi &&
+	git branch rename-ln &&
 
 	echo hello >>a &&
 	cp a d/e &&
@@ -260,16 +257,12 @@ test_expect_success 'setup 8' '
 	git add e &&
 	test_tick &&
 	git commit -m "rename a->e" &&
-	if test_have_prereq SYMLINKS
-	then
-		git checkout rename-ln &&
-		git mv a e &&
-		ln -s e a &&
-		git add a e &&
-		test_tick &&
-		git commit -m "rename a->e, symlink a->e" &&
-		oln=`printf e | git hash-object --stdin`
-	fi
+	git checkout rename-ln &&
+	git mv a e &&
+	test_ln_s_add e a &&
+	test_tick &&
+	git commit -m "rename a->e, symlink a->e" &&
+	oln=`printf e | git hash-object --stdin`
 '
 
 test_expect_success 'setup 9' '
@@ -569,28 +562,25 @@ test_expect_success 'merge-recursive copy vs. rename' '
 	test_cmp expected actual
 '
 
-if test_have_prereq SYMLINKS
-then
-	test_expect_failure 'merge-recursive rename vs. rename/symlink' '
-
-		git checkout -f rename &&
-		git merge rename-ln &&
-		( git ls-tree -r HEAD ; git ls-files -s ) >actual &&
-		(
-			echo "120000 blob $oln	a"
-			echo "100644 blob $o0	b"
-			echo "100644 blob $o0	c"
-			echo "100644 blob $o0	d/e"
-			echo "100644 blob $o0	e"
-			echo "120000 $oln 0	a"
-			echo "100644 $o0 0	b"
-			echo "100644 $o0 0	c"
-			echo "100644 $o0 0	d/e"
-			echo "100644 $o0 0	e"
-		) >expected &&
-		test_cmp expected actual
-	'
-fi
+test_expect_failure 'merge-recursive rename vs. rename/symlink' '
+
+	git checkout -f rename &&
+	git merge rename-ln &&
+	( git ls-tree -r HEAD ; git ls-files -s ) >actual &&
+	(
+		echo "120000 blob $oln	a"
+		echo "100644 blob $o0	b"
+		echo "100644 blob $o0	c"
+		echo "100644 blob $o0	d/e"
+		echo "100644 blob $o0	e"
+		echo "120000 $oln 0	a"
+		echo "100644 $o0 0	b"
+		echo "100644 $o0 0	c"
+		echo "100644 $o0 0	d/e"
+		echo "100644 $o0 0	e"
+	) >expected &&
+	test_cmp expected actual
+'
 
 
 test_done