From 4173df5187c8ba8bc2cc1a215f25b284d70631da Mon Sep 17 00:00:00 2001 From: Adrian Ratiu Date: Mon, 12 Jan 2026 20:46:25 +0200 Subject: submodule: introduce extensions.submodulePathConfig The idea of this extension is to abstract away the submodule gitdir path implementation: everyone is expected to use the config and not worry about how the path is computed internally, either in git or other implementations. With this extension enabled, the submodule..gitdir repo config becomes the single source of truth for all submodule gitdir paths. The submodule..gitdir config is added automatically for all new submodules when this extension is enabled. Git will throw an error if the extension is enabled and a config is missing, advising users how to migrate. Migration is manual for now. E.g. to add a missing config entry for an existing "foo" module: git config submodule.foo.gitdir .git/modules/foo Suggested-by: Junio C Hamano Suggested-by: Phillip Wood Suggested-by: Patrick Steinhardt Signed-off-by: Adrian Ratiu Signed-off-by: Junio C Hamano --- submodule.c | 61 +++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 35 insertions(+), 26 deletions(-) (limited to 'submodule.c') diff --git a/submodule.c b/submodule.c index d937911fbc..f7af389c79 100644 --- a/submodule.c +++ b/submodule.c @@ -31,6 +31,7 @@ #include "commit-reach.h" #include "read-cache-ll.h" #include "setup.h" +#include "advice.h" static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF; static int initialized_fetch_ref_tips; @@ -2164,8 +2165,9 @@ int submodule_move_head(const char *path, const char *super_prefix, if (validate_submodule_git_dir(git_dir, sub->name) < 0) die(_("refusing to create/use '%s' in " - "another submodule's git dir"), - git_dir); + "another submodule's git dir. " + "Enabling extensions.submodulePathConfig " + "should fix this."), git_dir); free(git_dir); } } else { @@ -2576,30 +2578,37 @@ cleanup: void submodule_name_to_gitdir(struct strbuf *buf, struct repository *r, const char *submodule_name) { - /* - * NEEDSWORK: The current way of mapping a submodule's name to - * its location in .git/modules/ has problems with some naming - * schemes. For example, if a submodule is named "foo" and - * another is named "foo/bar" (whether present in the same - * superproject commit or not - the problem will arise if both - * superproject commits have been checked out at any point in - * time), or if two submodule names only have different cases in - * a case-insensitive filesystem. - * - * There are several solutions, including encoding the path in - * some way, introducing a submodule..gitdir config in - * .git/config (not .gitmodules) that allows overriding what the - * gitdir of a submodule would be (and teach Git, upon noticing - * a clash, to automatically determine a non-clashing name and - * to write such a config), or introducing a - * submodule..gitdir config in .gitmodules that repo - * administrators can explicitly set. Nothing has been decided, - * so for now, just append the name at the end of the path. - */ - repo_git_path_append(r, buf, "modules/"); - strbuf_addstr(buf, submodule_name); + if (!r->repository_format_submodule_path_cfg) { + /* + * If extensions.submodulePathConfig is disabled, + * continue to use the plain path. + */ + repo_git_path_append(r, buf, "modules/%s", submodule_name); + } else { + const char *gitdir; + char *key; + int ret; - if (validate_submodule_git_dir(buf->buf, submodule_name) < 0) + /* Otherwise the extension is enabled, so use the gitdir config. */ + key = xstrfmt("submodule.%s.gitdir", submodule_name); + ret = repo_config_get_string_tmp(r, key, &gitdir); + FREE_AND_NULL(key); + + if (ret) + die(_("the 'submodule.%s.gitdir' config does not exist for module '%s'. " + "Please ensure it is set, for example by running something like: " + "'git config submodule.%s.gitdir .git/modules/%s'. For details " + "see the extensions.submodulePathConfig documentation."), + submodule_name, submodule_name, submodule_name, submodule_name); + + strbuf_addstr(buf, gitdir); + } + + /* validate because users might have modified the config */ + if (validate_submodule_git_dir(buf->buf, submodule_name)) { + advise(_("enabling extensions.submodulePathConfig might fix the " + "following error, if it's not already enabled.")); die(_("refusing to create/use '%s' in another submodule's " - "git dir"), buf->buf); + " git dir."), buf->buf); + } } -- cgit v1.3