t1507: run commands within test_expect_success

The expected test style is to have all commands tested within a
test_expect_success block. Move the generation of the 'expect' text into
their corresponding blocks. While we're at it, insert a second
`commit=$(git rev-parse HEAD)` into the next test case so that it's
clear where $commit is coming from.

The biggest advantage of doing this is that we now check the return code
of `git rev-parse HEAD` so we can catch it in case it fails.

This patch is best viewed with `--color-moved --ignore-all-space`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1507-rev-parse-upstream.sh

@@ -225,32 +225,32 @@ test_expect_success '@{u} works when tracking a local branch' '
 	test_cmp expect actual
 '
 
-commit=$(git rev-parse HEAD)
-cat >expect <<EOF
-commit $commit
-Reflog: master@{0} (C O Mitter <committer@example.com>)
-Reflog message: branch: Created from HEAD
-Author: A U Thor <author@example.com>
-Date:   Thu Apr 7 15:15:13 2005 -0700
-
-    3
-EOF
 test_expect_success 'log -g other@{u}' '
+	commit=$(git rev-parse HEAD) &&
+	cat >expect <<-EOF &&
+	commit $commit
+	Reflog: master@{0} (C O Mitter <committer@example.com>)
+	Reflog message: branch: Created from HEAD
+	Author: A U Thor <author@example.com>
+	Date:   Thu Apr 7 15:15:13 2005 -0700
+
+	    3
+	EOF
 	git log -1 -g other@{u} >actual &&
 	test_cmp expect actual
 '
 
-cat >expect <<EOF
-commit $commit
-Reflog: master@{Thu Apr 7 15:17:13 2005 -0700} (C O Mitter <committer@example.com>)
-Reflog message: branch: Created from HEAD
-Author: A U Thor <author@example.com>
-Date:   Thu Apr 7 15:15:13 2005 -0700
-
-    3
-EOF
-
 test_expect_success 'log -g other@{u}@{now}' '
+	commit=$(git rev-parse HEAD) &&
+	cat >expect <<-EOF &&
+	commit $commit
+	Reflog: master@{Thu Apr 7 15:17:13 2005 -0700} (C O Mitter <committer@example.com>)
+	Reflog message: branch: Created from HEAD
+	Author: A U Thor <author@example.com>
+	Date:   Thu Apr 7 15:15:13 2005 -0700
+
+	    3
+	EOF
 	git log -1 -g other@{u}@{now} >actual &&
 	test_cmp expect actual
 '