Re: [PATCH 1/2] reset: handle submodule with trailing slash

On Wed, Sep 11, 2013 at 6:08 PM, John Keeping [off-list ref] wrote:

quoted

quoted

-- >8 --

diff --git a/builtin/reset.c b/builtin/reset.c
index 9efac0f..800117f 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c

@@ -143,7 +143,6 @@ static int read_from_tree(const struct pathspec *pathspec,
        opt.output_format = DIFF_FORMAT_CALLBACK;
        opt.format_callback = update_index_from_diff;

-       read_cache();
        if (do_diff_cache(tree_sha1, &opt))
                return 1;
        diffcore_std(&opt);

@@ -169,7 +168,7 @@ static void set_reflog_message(struct strbuf *sb, const char *action,

 static void die_if_unmerged_cache(int reset_type)
 {
-       if (is_merge() || read_cache() < 0 || unmerged_cache())
+       if (is_merge() || unmerged_cache())
                die(_("Cannot do a %s reset in the middle of a merge."),
                    _(reset_type_names[reset_type]));

reset --soft does not go through these code paths (i.e. it does not
need index at all). If we fail to load index index in "reset --soft" I
think it's ok to die(). Corrupt index is fatal anyway. But "reset
--soft" now has to pay the cost to load index, which could be slow
when the index is big. Assuming nobody does "reset --soft" that often
I think this is OK.

Alternatively we could load index lazily in _CHEAP code only when we
see trailing slashes, then replace these read_cache() with
read_cache_unless_its_already_loaded_earlier() or something.

read_cache() already has an early return if the index is already loaded
so I don't think we need to worry about a special function for that.

I'm not sure it's worth optimizing this case too heavily, but it might
be a nice change to make parse_pathspec() not rely on the index being
loaded before it is called with certain flags.

Yeah I ddin't check. I agree putting read_cache() in _CHEAP code
sounds nice. We won't need to worry about forgotten read_cache()
elsewhere.
-- 
Duy