mailmap tests: get rid of overly complex blame fuzzing

Change a test that used a custom fuzzing function since
bfdfa3d414 (t4203 (mailmap): stop hardcoding commit ids and dates,
2010-10-15) to just use the "blame --porcelain" output instead.

We could use the same pattern as 0ba9c9a0fb (t8008: rely on
rev-parse'd HEAD instead of sha1 value, 2017-07-26) does to do this,
but there wouldn't be any point. We're not trying to test "blame"
output here in general, just that "blame" pays attention to the
mailmap.

So it's sufficient to get the blamed line(s) and authors from the
output, which is much easier with the "--porcelain" option.

It would still be possible for there to be a bug in "blame" such that
it uses the mailmap for its "--porcelain" output, but not the regular
output. Let's test for that simply by checking if specifying the
mailmap changes the output.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4203-mailmap.sh

@@ -4,14 +4,6 @@ test_description='.mailmap configurations'
 
 . ./test-lib.sh
 
-fuzz_blame () {
-	sed "
-		s/$_x05[0-9a-f][0-9a-f][0-9a-f]/OBJID/g
-		s/$_x05[0-9a-f][0-9a-f]/OBJI/g
-		s/[-0-9]\{10\} [:0-9]\{8\} [-+][0-9]\{4\}/DATE/g
-	" "$@"
-}
-
 test_expect_success 'setup commits and contacts file' '
 	echo one >one &&
 	git add one &&
@@ -630,24 +622,42 @@ test_expect_success 'Only grep replaced author with --use-mailmap' '
 	test_must_be_empty actual
 '
 
-test_expect_success 'Blame output (complex mapping)' '
+test_expect_success 'Blame --porcelain output (complex mapping)' '
 	test_config mailmap.file complex.map &&
 
 	cat >expect <<-EOF &&
-	^OBJI ($GIT_AUTHOR_NAME     DATE 1) one
-	OBJID (Some Dude    DATE 2) two
-	OBJID (Other Author DATE 3) three
-	OBJID (Other Author DATE 4) four
-	OBJID (Santa Claus  DATE 5) five
-	OBJID (Santa Claus  DATE 6) six
-	OBJID (CTO          DATE 7) seven
+	1 1 1
+	A U Thor
+	2 2 1
+	Some Dude
+	3 3 1
+	Other Author
+	4 4 1
+	Other Author
+	5 5 1
+	Santa Claus
+	6 6 1
+	Santa Claus
+	7 7 1
+	CTO
 	EOF
 
-	git blame one >actual &&
-	fuzz_blame actual >actual.fuzz &&
+	git blame --porcelain one >actual.blame &&
+	grep -E \
+		-e "[0-9]+ [0-9]+ [0-9]+$" \
+		-e "^author .*$" \
+		actual.blame >actual.grep &&
+	cut -d " " -f2-4 <actual.grep >actual.fuzz &&
 	test_cmp expect actual.fuzz
 '
 
+test_expect_success 'Blame output (complex mapping)' '
+	git -c mailmap.file=complex.map blame one >a &&
+	git blame one >b &&
+	test_file_not_empty a &&
+	! cmp a b
+'
+
 test_expect_success 'commit --author honors mailmap' '
 	test_config mailmap.file complex.map &&