t4011: modernise style

Match the style to more modern test scripts, namely:

 - The first line of each test has prereq, title and opening sq for the
   script body.  This makes the test shorter while reducing the need for
   backslashes.

 - Be prepared for the case in which the previous test may have failed.
   If a test wants to start from not having "frotz" that the previous test
   may have created, write "rm -f frotz", not "rm frotz".

 - Prepare the expected output inside your own test.

 - The order of comparison to check the result is "diff expected actual",
   so that the output will show how the output from the git you just broke
   is different from what is expected.

 - Write no SP between redirection '>' (or '<' for that matter) and the
   filename.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4011-diff-symlink.sh

@@ -9,7 +9,8 @@ test_description='Test diff of symlinks.
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/diff-lib.sh
 
-cat > expected << EOF
+test_expect_success SYMLINKS 'diff new symlink' '
+	cat >expected <<-\EOF &&
 	diff --git a/frotz b/frotz
 	new file mode 120000
 	index 0000000..7c465af
@@ -19,23 +20,22 @@ index 0000000..7c465af
 	+xyzzy
 	\ No newline at end of file
 	EOF
-
-test_expect_success SYMLINKS \
-    'diff new symlink' \
-    'ln -s xyzzy frotz &&
+	ln -s xyzzy frotz &&
 	git update-index &&
 	tree=$(git write-tree) &&
 	git update-index --add frotz &&
 	GIT_DIFF_OPTS=--unified=0 git diff-index -M -p $tree >current &&
-    compare_diff_patch current expected'
+	compare_diff_patch expected current
+'
 
-test_expect_success SYMLINKS \
-    'diff unchanged symlink' \
-    'tree=$(git write-tree) &&
+test_expect_success SYMLINKS 'diff unchanged symlink'  '
+	tree=$(git write-tree) &&
 	git update-index frotz &&
-    test -z "$(git diff-index --name-only $tree)"'
+	test -z "$(git diff-index --name-only $tree)"
+'
 
-cat > expected << EOF
+test_expect_success SYMLINKS 'diff removed symlink' '
+	cat >expected <<-\EOF &&
 	diff --git a/frotz b/frotz
 	deleted file mode 120000
 	index 7c465af..0000000
@@ -45,24 +45,22 @@ index 7c465af..0000000
 	-xyzzy
 	\ No newline at end of file
 	EOF
-
-test_expect_success SYMLINKS \
-    'diff removed symlink' \
-    'mv frotz frotz2 &&
+	mv frotz frotz2 &&
 	git diff-index -M -p $tree >current &&
-    compare_diff_patch current expected'
+	compare_diff_patch expected current
+'
 
-cat > expected << EOF
+test_expect_success SYMLINKS 'diff identical, but newly created symlink' '
+	cat >expected <<-\EOF &&
 	diff --git a/frotz b/frotz
 	EOF
-
-test_expect_success SYMLINKS \
-    'diff identical, but newly created symlink' \
-    'ln -s xyzzy frotz &&
+	ln -s xyzzy frotz &&
 	git diff-index -M -p $tree >current &&
-    compare_diff_patch current expected'
+	compare_diff_patch expected current
+'
 
-cat > expected << EOF
+test_expect_success SYMLINKS 'diff different symlink' '
+	cat >expected <<-\EOF &&
 	diff --git a/frotz b/frotz
 	index 7c465af..df1db54 120000
 	--- a/frotz
@@ -73,21 +71,19 @@ index 7c465af..df1db54 120000
 	+yxyyz
 	\ No newline at end of file
 	EOF
-
-test_expect_success SYMLINKS \
-    'diff different symlink' \
-    'rm frotz &&
+	rm -f frotz &&
 	ln -s yxyyz frotz &&
 	git diff-index -M -p $tree >current &&
-    compare_diff_patch current expected'
+	compare_diff_patch expected current
+'
 
-test_expect_success SYMLINKS \
-    'diff symlinks with non-existing targets' \
-    'ln -s narf pinky &&
+test_expect_success SYMLINKS 'diff symlinks with non-existing targets' '
+	ln -s narf pinky &&
 	ln -s take\ over brain &&
 	test_must_fail git diff --no-index pinky brain >output 2>output.err &&
 	grep narf output &&
-    ! grep error output.err'
+	! test -s output.err
+'
 
 test_expect_success SYMLINKS 'setup symlinks with attributes' '
 	echo "*.bin diff=bin" >>.gitattributes &&
@@ -96,7 +92,8 @@ test_expect_success SYMLINKS 'setup symlinks with attributes' '
 	git add -N file.bin link.bin
 '
 
-cat >expect <<'EOF'
+test_expect_success SYMLINKS 'symlinks do not respect userdiff config by path' '
+	cat >expect <<-\EOF &&
 	diff --git a/file.bin b/file.bin
 	index e69de29..d95f3ad 100644
 	Binary files a/file.bin and b/file.bin differ
@@ -108,7 +105,6 @@ index e69de29..dce41ec 120000
 	+file.bin
 	\ No newline at end of file
 	EOF
-test_expect_success SYMLINKS 'symlinks do not respect userdiff config by path' '
 	git config diff.bin.binary true &&
 	git diff file.bin link.bin >actual &&
 	test_cmp expect actual