Re: [PATCH v7 4/8] worktree: simplify find_shared_symref() memory ownership model

On Wed, Dec 1, 2021 at 7:13 PM Eric Sunshine [off-list ref] wrote:

If we instead hoist ownership of `worktrees` up to execute_commands()
-- which calls execute_commands_atomic() or
execute_commands_non_atomic() -- then we can get by with retrieving
the worktrees just once, and all those noise changes in update() can
be dropped since it will no longer be responsible for allocating or
freeing `worktrees`. For instance:

    static void execute_commands(...)
    {
        struct worktree **worktrees;
        ...
        worktrees = get_worktrees();
         if (use_atomic)
            execute_commands_atomic(commands, si, worktrees);
        else
            execute_commands_non_atomic(commands, si, worktrees);
        free_worktrees(worktrees);
        ...
    }

and then execute_commands_atomic() and execute_commands_non_atomic()
can pass `worktrees` along to update().

By the way, I wouldn't typically recommend this sort of change for
public API since it probably exposes too much implementation detail to
callers, but as these are all private (static) worker functions --
with very few callers, moreover -- I don't find it terribly worrying.