Re: [PATCH 08/16] update submodules: add depopulate_submodule

[Stefan Beller <sbeller@google.com>]

On Thu, Nov 17, 2016 at 2:42 PM, Stefan Beller <sbeller@google.com> wrote:
>
> I think I'll just write this functionality in C and optionally expose
> it via the submodule--helper,
> such that the user facing git-submodule.sh only has to call that helper.

I think it will roughly look like this:
(white space mangled)


commit e72ef244c667920c874247aa32aa55845500aac8
Author: Stefan Beller <sbeller@google.com>
Date:   Thu Nov 17 16:14:46 2016 -0800

    submodule--helper: add intern-git-dir function

    When a submodule has its git dir inside the working dir, the submodule
    support for checkout that we plan to add in a later patch will fail.

    Add functionality to migrate the git directory to be embedded
    into the superprojects git directory.

    Signed-off-by: Stefan Beller <sbeller@google.com>

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 4beeda5..4f31100 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1076,6 +1076,21 @@ static int resolve_remote_submodule_branch(int
argc, const char **argv,
        return 0;
 }

+static int intern_git_dir(int argc, const char **argv, const char *prefix)
+{
+       int i;
+       struct pathspec pathspec;
+       struct module_list list = MODULE_LIST_INIT;
+
+       if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+               return 1;
+
+       for (i = 0; i < list.nr; i++)
+               migrate_submodule_gitdir(list.entries[i]->name);
+
+       return 0;
+}
+
 struct cmd_struct {
        const char *cmd;
        int (*fn)(int, const char **, const char *);
@@ -1090,7 +1105,8 @@ static struct cmd_struct commands[] = {
        {"resolve-relative-url", resolve_relative_url},
        {"resolve-relative-url-test", resolve_relative_url_test},
        {"init", module_init},
-       {"remote-branch", resolve_remote_submodule_branch}
+       {"remote-branch", resolve_remote_submodule_branch},
+       {"intern-git-dir", intern_git_dir}
 };

 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
diff --git a/submodule.c b/submodule.c
index 45b9060..e513bba 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1335,3 +1335,42 @@ void prepare_submodule_repo_env(struct argv_array *out)
        }
        argv_array_push(out, "GIT_DIR=.git");
 }
+
+/*
+ * Migrate the given submodule (and all its submodules recursively) from
+ * having its git directory within the working tree to the git dir nested
+ * in its superprojects git dir under modules/.
+ */
+void migrate_submodule_gitdir(const char *path)
+{
+       char *old_git_dir;
+       const char *new_git_dir;
+       const struct submodule *sub;
+
+       struct child_process cp = CHILD_PROCESS_INIT;
+       cp.git_cmd = 1;
+       cp.no_stdin = 1;
+       cp.dir = path;
+       argv_array_pushl(&cp.args, "submodule", "foreach", "--recursive",
+                       "git", "submodule--helper" "intern-git-dir", NULL);
+
+       if (run_command(&cp))
+               die(_("Could not migrate git directory in submodule '%s'"),
+                   path);
+
+       old_git_dir = xstrfmt("%s/.git", path);
+       if (read_gitfile(old_git_dir))
+               /* If it is an actual gitfile, it doesn't need migration. */
+               goto out;
+
+       sub = submodule_from_path(null_sha1, path);
+       new_git_dir = git_common_path("modules/%s", sub->name);
+
+       if (rename(old_git_dir, new_git_dir) < 0)
+               die_errno(_("Could not migrate git directory from %s to %s"),
+                       old_git_dir, new_git_dir);
+
+       connect_work_tree_and_git_dir(path, new_git_dir);
+out:
+       free(old_git_dir);
+}
diff --git a/submodule.h b/submodule.h
index aac202c..143ec18 100644
--- a/submodule.h
+++ b/submodule.h
@@ -90,5 +90,6 @@ extern int parallel_submodules(void);
  * retaining any config in the environment.
  */
 extern void prepare_submodule_repo_env(struct argv_array *out);
+extern void migrate_submodule_gitdir(const char *path);

 #endif