Add some basic tests of rev-list --pretty=format

These could stand to be a little more complex, but it should
at least catch obvious problems (like the recently fixed %ct
bug).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

t/t6006-rev-list-format.sh

+#!/bin/sh
+
+test_description='git-rev-list --pretty=format test'
+
+. ./test-lib.sh
+
+test_tick
+test_expect_success 'setup' '
+touch foo && git-add foo && git-commit -m "added foo" &&
+  echo changed >foo && git-commit -a -m "changed foo"
+'
+
+# usage: test_format name format_string <expected_output
+test_format() {
+	cat >expect.$1
+	test_expect_success "format $1" "
+git-rev-list --pretty=format:$2 master >output.$1 &&
+git-diff expect.$1 output.$1
+"
+}
+
+test_format hash %H%n%h <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+131a310eb913d107dd3c09a65d1651175898735d
+131a310
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+86c75cf
+EOF
+
+test_format tree %T%n%t <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+fe722612f26da5064c32ca3843aa154bdb0b08a0
+fe72261
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+4d5fcadc293a348e88f777dc0920f11e7d71441c
+4d5fcad
+EOF
+
+test_format parents %P%n%p <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+86c75cfd708a0e5868dc876ed5b8bb66c80b4873 
+86c75cf 
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+86c75cf 
+86c75cf 
+EOF
+
+# we don't test relative here
+test_format author %an%n%ae%n%ad%n%aD%n%at <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+A U Thor
+author@example.com
+Thu Apr 7 15:13:13 2005 -0700
+Thu, 7 Apr 2005 15:13:13 -0700
+1112911993
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+A U Thor
+author@example.com
+Thu Apr 7 15:13:13 2005 -0700
+Thu, 7 Apr 2005 15:13:13 -0700
+1112911993
+EOF
+
+test_format committer %cn%n%ce%n%cd%n%cD%n%ct <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+C O Mitter
+committer@example.com
+Thu Apr 7 15:13:13 2005 -0700
+Thu, 7 Apr 2005 15:13:13 -0700
+1112911993
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+C O Mitter
+committer@example.com
+Thu Apr 7 15:13:13 2005 -0700
+Thu, 7 Apr 2005 15:13:13 -0700
+1112911993
+EOF
+
+test_format encoding %e <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+<unknown>
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+<unknown>
+EOF
+
+test_format subject %s <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+changed foo
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+added foo
+EOF
+
+test_format body %b <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+<unknown>
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+<unknown>
+EOF
+
+test_format colors %Credfoo%Cgreenbar%Cbluebaz%Cresetxyzzy <<'EOF'
+commit 131a310eb913d107dd3c09a65d1651175898735d
+foobarbazxyzzy
+commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
+foobarbazxyzzy
+EOF
+
+test_done