submodule: fixup nested submodules after moving the submodule

connect_work_tree_and_git_dir is used to connect a submodule worktree with
its git directory and vice versa after events that require a reconnection
such as moving around the working tree. As submodules can have nested
submodules themselves, we'd also want to fix the nested submodules when
asked to. Add an option to recurse into the nested submodules and connect
them as well.

As submodules are identified by their name (which determines their git
directory in relation to their superproject's git directory) internally
and by their path in the working tree of the superproject, we need to
make sure that the mapping of name <-> path is kept intact. We can do
that in the git-mv command by writing out the gitmodules file first
and then forcing a reload of the submodule config machinery.

Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 57 insertions, 3 deletions

diff --git a/dir.c b/dir.c
index ce6e50d..4f401b6 100644
--- a/dir.c
+++ b/dir.c
@@ -19,6 +19,7 @@
 #include "varint.h"
 #include "ewah/ewok.h"
 #include "fsmonitor.h"
+#include "submodule-config.h"
 
 /*
  * Tells read_directory_recursive how a file or directory should be treated.
@@ -2988,8 +2989,57 @@ void untracked_cache_add_to_index(struct index_state *istate,
 	untracked_cache_invalidate_path(istate, path);
 }
 
-/* Update gitfile and core.worktree setting to connect work tree and git dir */
-void connect_work_tree_and_git_dir(const char *work_tree_, const char *git_dir_)
+static void connect_wt_gitdir_in_nested(const char *sub_worktree,
+					const char *sub_gitdir)
+{
+	int i;
+	struct repository subrepo;
+	struct strbuf sub_wt = STRBUF_INIT;
+	struct strbuf sub_gd = STRBUF_INIT;
+
+	const struct submodule *sub;
+
+	/* If the submodule has no working tree, we can ignore it. */
+	if (repo_init(&subrepo, sub_gitdir, sub_worktree))
+		return;
+
+	if (repo_read_index(&subrepo) < 0)
+		die("index file corrupt in repo %s", subrepo.gitdir);
+
+	for (i = 0; i < subrepo.index->cache_nr; i++) {
+		const struct cache_entry *ce = subrepo.index->cache[i];
+
+		if (!S_ISGITLINK(ce->ce_mode))
+			continue;
+
+		while (i + 1 < subrepo.index->cache_nr &&
+		       !strcmp(ce->name, subrepo.index->cache[i + 1]->name))
+			/*
+			 * Skip entries with the same name in different stages
+			 * to make sure an entry is returned only once.
+			 */
+			i++;
+
+		sub = submodule_from_path(&subrepo, &null_oid, ce->name);
+		if (!sub || !is_submodule_active(&subrepo, ce->name))
+			/* .gitmodules broken or inactive sub */
+			continue;
+
+		strbuf_reset(&sub_wt);
+		strbuf_reset(&sub_gd);
+		strbuf_addf(&sub_wt, "%s/%s", sub_worktree, sub->path);
+		strbuf_addf(&sub_gd, "%s/modules/%s", sub_gitdir, sub->name);
+
+		connect_work_tree_and_git_dir(sub_wt.buf, sub_gd.buf, 1);
+	}
+	strbuf_release(&sub_wt);
+	strbuf_release(&sub_gd);
+	repo_clear(&subrepo);
+}
+
+void connect_work_tree_and_git_dir(const char *work_tree_,
+				   const char *git_dir_,
+				   int recurse_into_nested)
 {
 	struct strbuf gitfile_sb = STRBUF_INIT;
 	struct strbuf cfg_sb = STRBUF_INIT;
@@ -3019,6 +3069,10 @@ void connect_work_tree_and_git_dir(const char *work_tree_, const char *git_dir_)
 	strbuf_release(&gitfile_sb);
 	strbuf_release(&cfg_sb);
 	strbuf_release(&rel_path);
+
+	if (recurse_into_nested)
+		connect_wt_gitdir_in_nested(work_tree, git_dir);
+
 	free(work_tree);
 	free(git_dir);
 }
@@ -3032,5 +3086,5 @@ void relocate_gitdir(const char *path, const char *old_git_dir, const char *new_
 		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);
+	connect_work_tree_and_git_dir(path, new_git_dir, 0);
 }