[PATCH 5/6] worktree move: refuse to move worktrees with submodules

[Nguyễn Thái Ngọc Duy]

Submodules contains .git files with relative paths. After a worktree
move, these files need to be updated or they may point to nowhere.

This is a bandage patch to make sure "worktree move" don't break
people's worktrees by accident. When .git file update code is in
place, this validate_no_submodules() could be removed.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
 builtin/worktree.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 116507e47e..825b3e9d9a 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -526,6 +526,27 @@ static int unlock_worktree(int ac, const char **av, const 
char *prefix)
        return ret;
 }
 
+static void validate_no_submodules(const struct worktree *wt)
+{
+       struct index_state istate = {0};
+       int i, found_submodules = 0;
+
+       if (read_index_from(&istate, worktree_git_path(wt, "index")) > 0) {
+               for (i = 0; i < istate.cache_nr; i++) {
+                       struct cache_entry *ce = istate.cache[i];
+
+                       if (S_ISGITLINK(ce->ce_mode)) {
+                               found_submodules = 1;
+                               break;
+                       }
+               }
+       }
+       discard_index(&istate);
+
+       if (found_submodules)
+               die(_("This working tree contains submodules and cannot be 
moved yet"));
+}
+
 static int move_worktree(int ac, const char **av, const char *prefix)
 {
        struct option options[] = {
@@ -564,6 +585,8 @@ static int move_worktree(int ac, const char **av, const 
char *prefix)
        if (validate_worktree(wt, 0))
                return -1;
 
+       validate_no_submodules(wt);
+
        if (is_directory(dst.buf)) {
                const char *sep = find_last_dir_sep(wt->path);
 
-- 
2.11.0.157.gd943d85