t8003: factor setup out of coalesce test

In preparation for adding more tests of blame's coalesce code, let's
split the setup out from the first test, and give each of the commits
a more meaningful name:

  - $orig for the original source that added the lines

  - $split for the version where they are split apart

  - $final for the final version that re-joins them

That's not strictly necessary, but makes the follow-on tests less
brittle than relying on HEAD^, etc, to name the commits.

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

t/t8003-blame-corner-cases.sh

@@ -274,14 +274,14 @@ test_expect_success 'blame file with CRLF core.autocrlf=true' '
 	grep "A U Thor" actual
 '
 
-test_expect_success 'blame coalesce' '
+test_expect_success 'setup coalesce tests' '
 	cat >giraffe <<-\EOF &&
 	ABC
 	DEF
 	EOF
 	git add giraffe &&
 	git commit -m "original file" &&
-	oid=$(git rev-parse HEAD) &&
+	orig=$(git rev-parse HEAD) &&
 
 	cat >giraffe <<-\EOF &&
 	ABC
@@ -290,6 +290,7 @@ test_expect_success 'blame coalesce' '
 	EOF
 	git add giraffe &&
 	git commit -m "interior SPLIT line" &&
+	split=$(git rev-parse HEAD) &&
 
 	cat >giraffe <<-\EOF &&
 	ABC
@@ -297,13 +298,16 @@ test_expect_success 'blame coalesce' '
 	EOF
 	git add giraffe &&
 	git commit -m "same contents as original" &&
+	final=$(git rev-parse HEAD)
+'
 
+test_expect_success 'blame coalesce' '
 	cat >expect <<-EOF &&
-	$oid 1 1 2
-	$oid 2 2
+	$orig 1 1 2
+	$orig 2 2
 	EOF
-	git blame --porcelain giraffe >actual.raw &&
-	grep "^$oid" actual.raw >actual &&
+	git blame --porcelain $final giraffe >actual.raw &&
+	grep "^$orig" actual.raw >actual &&
 	test_cmp expect actual
 '