On 2/15/2022 10:59 AM, Jeff Hostetler via GitGitGadget wrote:
> From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
>
> Teach FSMonitor daemon on Windows to recognize shortname paths as
> aliases of normal longname paths. FSMonitor clients, such as `git
> status`, should receive the longname spelling of changed files (when
> possible).
>
> Sometimes we receive FS events using the shortname, such as when a CMD
> shell runs "RENAME GIT~1 FOO" or "RMDIR GIT~1". The FS notification
> arrives using whatever combination of long and shortnames were used by
> the other process. (Shortnames do seem to be case normalized,
> however.)
>
> Use Windows GetLongPathNameW() to try to map the pathname spelling in
> the notification event into the normalized longname spelling. (This
> can fail if the file/directory is deleted, moved, or renamed, because
> we are asking the FS for the mapping in response to the event and
> after it has already happened, but we try.)
I recall when we first discovered that this was important for users.
I'm glad we haven't needed to worry about it since this fix.
> Special case the shortname spelling of ".git" to avoid under-reporting
> these events.
This is particularly critical due to the case of deleting the .git
directory being really important to catch, but GetLongPathNameW()
won't work in that case.
> + if (!GetLongPathNameW(buf_in, buf_out, MAX_PATH)) {
> + /*
> + * The shortname to longname conversion can fail for
> + * various reasons, for example if the file has been
> + * deleted. (That is, if we just received a
> + * delete-file notification event and the file is
> + * already gone, we can't ask the file system to
> + * lookup the longname for it. Likewise, for moves
> + * and renames where we are given the old name.)
> + *
> + * NEEDSWORK: Since deleting or moving a file or
> + * directory by shortname is rather obscure, I'm going
> + * ignore the failure and ask the caller to report the
> + * original relative path. This seemds kinder than
s/seemds/seems/
> + * failing here and forcing a resync.
> + */
> + return GRR_NO_CONVERSION_NEEDED;
> + }
This NEEDSWORK is something I saw while reading that makes it seem
like we _need_ to do something here. I think this is an appropriate
short-term solution that we can revisit if necessary. I don't
anticipate that actually being the case, though.
Thanks,
-Stolee
