[PATCH v3] submodule: suppress checking for file name and ref ambiguity for object ids

From: Orgad Shaneh <orgads@gmail.com>

The argv argument of collect_changed_submodules() contains obly object ids (the objects references of all the refs).

Notify setup_revisions() that the input is not filenames by passing assume_dashdash, so it can avoid redundant stat for each ref.

Also suppress refname_ambiguity flag to avoid filesystem lookups for each object. Similar logic can be found in cat-file, pack-objects and more.

Signed-off-by: Orgad Shaneh <orgads@gmail.com>
---
    submodule: suppress checking for file name and ref ambiguity for object
    ids
    
    The argv argument of collect_changed_submodules() contains obly object
    ids (submodule references).
    
    Notify setup_revisions() that the input is not filenames by passing
    assume_dashdash, so it can avoid redundant stat for each ref.
    
    A better improvement would be to pass oid_array instead of stringified
    argv, but that will require a larger change, which can be done later.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-725%2Forgads%2Fsubmodule-not-filename-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-725/orgads/submodule-not-filename-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/725

Range-diff vs v2:

 1:  501ce90e9a ! 1:  128a7244f9 submodule: suppress checking for file name ambiguity for object ids
     @@ Metadata
      Author: Orgad Shaneh <orgads@gmail.com>
      
       ## Commit message ##
     -    submodule: suppress checking for file name ambiguity for object ids
     +    submodule: suppress checking for file name and ref ambiguity for object ids
      
          The argv argument of collect_changed_submodules() contains obly object ids
          (the objects references of all the refs).
     @@ Commit message
          Notify setup_revisions() that the input is not filenames by passing
          assume_dashdash, so it can avoid redundant stat for each ref.
      
     -    A better improvement would be to pass oid_array instead of stringified argv,
     -    but that will require a larger change, which can be done later.
     +    Also suppress refname_ambiguity flag to avoid filesystem lookups for
     +    each object. Similar logic can be found in cat-file, pack-objects and more.
      
          Signed-off-by: Orgad Shaneh <orgads@gmail.com>
      
     @@ submodule.c: static void collect_changed_submodules(struct repository *r,
       {
       	struct rev_info rev;
       	const struct commit *commit;
     ++	int save_warning;
      +	struct setup_revision_opt s_r_opt = {
      +		.assume_dashdash = 1,
      +	};
       
     ++	save_warning = warn_on_object_refname_ambiguity;
     ++	warn_on_object_refname_ambiguity = 0;
       	repo_init_revisions(r, &rev, NULL);
      -	setup_revisions(argv->nr, argv->v, &rev, NULL);
      +	setup_revisions(argv->nr, argv->v, &rev, &s_r_opt);
     ++	warn_on_object_refname_ambiguity = save_warning;
       	if (prepare_revision_walk(&rev))
       		die(_("revision walk setup failed"));
       

 submodule.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)