Re: [PATCH v2] builtin/submodule--helper.c: handle missing submodule URLs
From: Eric Sunshine <hidden>
Date: 2023-05-24 18:49:14
On Wed, May 24, 2023 at 12:40 PM Taylor Blau [off-list ref] wrote:
In e0a862fdaf (submodule helper: convert relative URL to absolute URL if
needed, 2018-10-16), `prepare_to_clone_next_submodule()` lost the
ability to handle URL-less submodules, due to a change from:
if (repo_get_config_string_const(the_repostiory, sb.buf, &url))
url = sub->url;
to
if (repo_get_config_string_const(the_repostiory, sb.buf, &url)) {
if (starts_with_dot_slash(sub->url) ||
starts_with_dot_dot_slash(sub->url)) {
/* ... */
}
}
, which will segfault when `sub->url` is NULL, since both
`starts_with_dot_slash()` does not guard its arguments as non-NULL.
Guard the checks to both of the above functions by first whethers/first/first checking/
quoted hunk ↗ jump to hunk
`sub->url` is non-NULL. There is no need to check whether `sub` itself is NULL, since we already perform this check earlier in `prepare_to_clone_next_submodule()`. By adding a NULL-ness check on `sub->url`, we'll fall into the 'else' branch, setting `url` to `sub->url` (which is NULL). Before attempting to invoke `git submodule--helper clone`, check whether `url` is NULL, and die() if it is. Reported-by: Tribo Dar <redacted> Signed-off-by: Taylor Blau <redacted> ---diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c@@ -2024,14 +2024,17 @@ static int prepare_to_clone_next_submodule(const struct cache_entry *ce, - if (starts_with_dot_slash(sub->url) || - starts_with_dot_dot_slash(sub->url)) { + if (sub->url && (starts_with_dot_slash(sub->url) || + starts_with_dot_dot_slash(sub->url))) { url = resolve_relative_url(sub->url, NULL, 0); need_free_url = 1; } else url = sub->url; } + if (!url) + die(_("cannot clone submodule '%s' without a URL"), sub->name);
Good. The first version of this patch was more difficult to reason about due to its "error-at-a-distance" approach. This version is much cleaner and obvious.
quoted hunk ↗ jump to hunk
@@ -2065,11 +2068,11 @@ static int prepare_to_clone_next_submodule(const struct cache_entry *ce, strvec_pushf(&child->args, "--filter=%s", expand_list_objects_filter_spec(suc->update_data->filter_options)); + strvec_pushl(&child->args, "--url", url, NULL); if (suc->update_data->require_init) strvec_push(&child->args, "--require-init"); strvec_pushl(&child->args, "--path", sub->path, NULL); strvec_pushl(&child->args, "--name", sub->name, NULL); - strvec_pushl(&child->args, "--url", url, NULL);
This change is unnecessary now, isn't it? Or is there something nonobvious going on here?