largefiles: access to specific fields only if largefiles enabled (
issue4547)
Even if largefiles extension is enabled in a repository, "repo"
object, which isn't "largefiles.reposetup()"-ed, is passed to
overridden functions in the cases below unexpectedly, because
extensions are enabled for each repositories strictly.
(1) clone without -U:
(2) pull with -U:
(3) pull with --rebase:
combination of "enabled@src", "disabled@dst" and
"not-required@src" cause this situation.
largefiles requirement
@src @dst @src result
-------- -------- --------------- --------------------
enabled disabled not-required aborted unexpectedly
required requirement error (intentional)
-------- -------- --------------- --------------------
enabled enabled * success
-------- -------- --------------- --------------------
disabled enabled * success (only for "pull")
-------- -------- --------------- --------------------
disabled disabled not-required success
required requirement error (intentional)
-------- -------- --------------- --------------------
(4) update/revert with a subrepo disabling largefiles
In these cases, overridden functions cause accessing to largefiles
specific fields of not "largefiles.reposetup()"-ed "repo" object, and
execution is aborted.
- (1), (2), (4) cause accessing to "_lfstatuswriters" in
"getstatuswriter()" invoked via "updatelfiles()"
- (3) causes accessing to "_lfcommithooks" in "overriderebase()"
For safe accessing to these fields, this patch examines whether passed
"repo" object is "largefiles.reposetup()"-ed or not before accessing
to them.
This patch chooses examining existence of newly introduced
"_largefilesenabled" instead of "_lfcommithooks" and
"_lfstatuswriters" directly, because the former is better name for the
generic "largefiles is enabled in this repo" mark than the latter.
In the future, all other overridden functions should avoid largefiles
specific processing for efficiency, and "_largefilesenabled" is better
also for such purpose.
BTW, "lfstatus" can't be used for such purpose, because some code
paths set it forcibly regardless of existence of it in specified
"repo" object.