Re: [PATCH] remote-hg: add shared repo upgrade

Antoine Pelisse [off-list ref] writes:

From: Felipe Contreras <redacted>

6796d49 (remote-hg: use a shared repository store) introduced a bug by
making the shared repository '.git/hg', which is already used before
that patch, so clones that happened before that patch, fail after that
patch, because there's no shared Mercurial repo.

It's trivial to upgrade to the new organization by copying the Mercurial
repo from one of the remotes (e.g. 'origin'), so let's do so.

...
+        # check and upgrade old organization
+        hg_path = os.path.join(shared_path, '.hg')
+        if os.path.exists(shared_path) and not os.path.exists(hg_path):
+            repos = os.listdir(shared_path)
+            for x in repos:
+                local_hg = os.path.join(shared_path, x, 'clone', '.hg')
+                if not os.path.exists(local_hg):
+                    continue
+                shutil.copytree(local_hg, hg_path)

The log message talks about "one of the remotes (e.g. 'origin')" and
you are creating a copy of one that you encounter in os.listdir(); I
may be missing some underlying assumptions but I wonder what happens
after you copy and create hg_path directory, which does not change
in the loop, to the remaining iterations of the loop.  Is the untold
and obvious-to-those-who-are-familiar-with-this-codepath assumption
that it is guaranteed that there is at most one "*/clone/.hg" under
shared_path?

+        # setup shared repo (if not there)
+        try:
+            hg.peer(myui, {}, shared_path, create=True)
+        except error.RepoError:
+            pass
 
         if not os.path.exists(dirname):
             os.makedirs(dirname)