Taylor Blau [off-list ref] writes:

quoted

quoted

quoted

@@ -414,6 +414,7 @@ void prune_shallow(unsigned options)
 	} else {
 		unlink(git_path_shallow(the_repository));
 		rollback_lock_file(&shallow_lock);
+		reset_repository_shallow(the_repository);
 	}

Here, we reset only after we realize we cannot write the updated
shallow file.  Intended?

Yes, see this earlier discussion I had about it with Jonathan:
https://lore.kernel.org/git/20200416020509.225014-1-jonathantanmy@google.com/ (local).

I did, and then I asked the question, because I couldn't quite get
if JTan was asking a question similar to the one he asked earlier in
the message ("do you need a reset in the "else" branch as well?"),
or if he was saying what he sees there, "the opposite case", was
good.

Sorry for not being clear. My intention was to ask a question similar to
the earlier one - in this case, and in the previous case, I think that
the reset should happen no matter whether we execute the "if" case or
the "else" case, so we should just put it right after the entire "if"
statement.