rebase -m: fix serialization of strategy options

To store the strategy options rebase prepends " --" to each one and
writes them to a file. To load them it reads the file and passes the
contents to split_cmdline(). This roughly mimics the behavior of the
scripted rebase but has a couple of limitations, (1) options containing
whitespace are not properly preserved (this is true of the scripted
rebase as well) and (2) options containing '"' or '\' are incorrectly
parsed and may cause the parser to return an error.

Fix these limitations by quoting each option when they are stored so
that they can be parsed correctly. Now that "--preserve-merges" no
longer exist this change also stops prepending "--" to the options when
they are stored as that was an artifact of the scripted rebase.

These changes are backwards compatible so the files written by an older
version of git can still be read. They are also forwards compatible,
the file can still be parsed by recent versions of git as they treat the
"--" prefix as optional.

Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 22 insertions, 12 deletions

diff --git a/t/t3418-rebase-continue.sh b/t/t3418-rebase-continue.sh
index 130e2f9b55..42c3954125 100755
--- a/t/t3418-rebase-continue.sh
+++ b/t/t3418-rebase-continue.sh
@@ -62,29 +62,39 @@ test_expect_success 'rebase --continue remembers merge strategy and options' '
 	rm -fr .git/rebase-* &&
 	git reset --hard commit-new-file-F2-on-topic-branch &&
 	test_commit "commit-new-file-F3-on-topic-branch" F3 32 &&
-	test_when_finished "rm -fr test-bin funny.was.run" &&
+	test_when_finished "rm -fr test-bin" &&
 	mkdir test-bin &&
-	cat >test-bin/git-merge-funny <<-EOF &&
-	#!$SHELL_PATH
-	case "\$1" in --opt) ;; *) exit 2 ;; esac
-	shift &&
-	>funny.was.run &&
-	exec git merge-recursive "\$@"
+
+	write_script test-bin/git-merge-funny <<-\EOF &&
+	printf "[%s]\n" $# "$1" "$2" "$3" "$5" >actual
+	shift 3 &&
+	exec git merge-recursive "$@"
 	EOF
-	chmod +x test-bin/git-merge-funny &&
+
+	cat >expect <<-\EOF &&
+	[7]
+	[--option=arg with space]
+	[--op"tion\]
+	[--new
+	line ]
+	[--]
+	EOF
+
+	rm -f actual &&
 	(
 		PATH=./test-bin:$PATH &&
-		test_must_fail git rebase -s funny -Xopt main topic
+		test_must_fail git rebase -s funny -X"option=arg with space" \
+				-Xop\"tion\\ -X"new${LF}line " main topic
 	) &&
-	test -f funny.was.run &&
-	rm funny.was.run &&
+	test_cmp expect actual &&
+	rm actual &&
 	echo "Resolved" >F2 &&
 	git add F2 &&
 	(
 		PATH=./test-bin:$PATH &&
 		git rebase --continue
 	) &&
-	test -f funny.was.run
+	test_cmp expect actual
 '
 
 test_expect_success 'rebase -i --continue handles merge strategy and options' '