# Make git-rev-list and git-rev-parse argument parsing stricter

3 messages from 2006-01-25 to 2006-01-25. Participants: Linus Torvalds, Junio C Hamano.
Thread: https://gitlist.dev/t/3151

## Linus Torvalds, 2006-01-25 22:00

Subject: Make git-rev-list and git-rev-parse argument parsing stricter
Message-ID: <Pine.LNX.4.64.0601251655580.2644@evo.osdl.org>
URL: https://gitlist.dev/e/Pine.LNX.4.64.0601251655580.2644%40evo.osdl.org

```

If you pass it a filename without the "--" marker to separate it from
revision information and flags, we now require that the file in question
actually exists. This makes mis-typed revision information not be silently
just considered a strange filename.

With the "--" marker, you can continue to pass in filenames that do not
actually exists - useful for querying what happened to a file that you
no longer have in the repository.

[ All scripts should use the "--" format regardless, to make things
  unambiguous. So this change should not affect any existing tools ]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
----

I hit this the hard way when I was showing off git at Linux.Conf.Au 
yesterday, and I asked for

	git log v2.6.14..v2.6.16

which silently did nothing at all. The reason? I don't actually have a 
v2.6.16, the most recent version is 2.6.16-rc1. So it thought 
v2.6.14..v2.6.16 was a _filename_.

Now, normally, if you use the "proper" format (with the -- delimeter to 
mark where filenames start), you'd never have this ambiguity. But without 
the "--", the way I decided that we should disambiguate things is to 
verify that any filename given with the ambiguous shorthand version 
actually exists.

Comments?

diff --git a/rev-list.c b/rev-list.c
index d060966..e00e6fc 100644
--- a/rev-list.c
+++ b/rev-list.c
@@ -844,8 +844,12 @@ int main(int argc, const char **argv)
 			arg++;
 			limited = 1;
 		}
-		if (get_sha1(arg, sha1) < 0)
+		if (get_sha1(arg, sha1) < 0) {
+			struct stat st;
+			if (lstat(arg, &st) < 0)
+				die("'%s': %s", arg, strerror(errno));
 			break;
+		}
 		commit = get_commit_reference(arg, sha1, flags);
 		handle_one_commit(commit, &list);
 	}
diff --git a/rev-parse.c b/rev-parse.c
index 0c951af..7abad35 100644
--- a/rev-parse.c
+++ b/rev-parse.c
@@ -154,6 +154,7 @@ int main(int argc, char **argv)
 	const char *prefix = setup_git_directory();
 	
 	for (i = 1; i < argc; i++) {
+		struct stat st;
 		char *arg = argv[i];
 		char *dotdot;
 	
@@ -293,6 +294,8 @@ int main(int argc, char **argv)
 		}
 		if (verify)
 			die("Needed a single revision");
+		if (lstat(arg, &st) < 0)
+			die("'%s': %s", arg, strerror(errno));
 		as_is = 1;
 		show_file(arg);
 	}

```

## Linus Torvalds, 2006-01-25 22:02

Subject: git-whatchanged: exit out early on errors
Message-ID: <Pine.LNX.4.64.0601251700540.2644@evo.osdl.org>
URL: https://gitlist.dev/e/Pine.LNX.4.64.0601251700540.2644%40evo.osdl.org
In-Reply-To: <Pine.LNX.4.64.0601251655580.2644@evo.osdl.org>

```

If we get an error parsing the arguments, exit.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

This goes together with the previous diff - it just makes git-whatchanged 
exit gracefully when git-rev-parse errors out.

diff --git a/git-whatchanged.sh b/git-whatchanged.sh
index 80e2500..d4f985b 100755
--- a/git-whatchanged.sh
+++ b/git-whatchanged.sh
@@ -4,7 +4,7 @@ USAGE='[-p] [--max-count=<n>] [<since>..
 SUBDIRECTORY_OK='Yes'
 . git-sh-setup
 
-diff_tree_flags=$(git-rev-parse --sq --no-revs --flags "$@")
+diff_tree_flags=$(git-rev-parse --sq --no-revs --flags "$@") || exit
 test -z "$diff_tree_flags" &&
 	diff_tree_flags=$(git-repo-config --get whatchanged.difftree)
 test -z "$diff_tree_flags" &&

```

## Junio C Hamano, 2006-01-25 22:40

Subject: Re: Make git-rev-list and git-rev-parse argument parsing stricter
Message-ID: <7vhd7sorrw.fsf@assigned-by-dhcp.cox.net>
URL: https://gitlist.dev/e/7vhd7sorrw.fsf%40assigned-by-dhcp.cox.net
In-Reply-To: <Pine.LNX.4.64.0601251655580.2644@evo.osdl.org>

```
Linus Torvalds <torvalds@osdl.org> writes:

> If you pass it a filename without the "--" marker to separate it from
> revision information and flags, we now require that the file in question
> actually exists. This makes mis-typed revision information not be silently
> just considered a strange filename.
>...
> Comments?

I think it is a good safety measure.  People has to say "git
rev-list -- git-commit-script" if they are interested in
historical paths, but that is less common.  We could even go
stronger and always require '--', but that is probably too much
for normal use.  I like the balance you struck here.

```