devel-warn: add a prefix to all messages ("devel-warn: ") We want to make the origin and importance of the message clear to developers.

push: acquire local 'wlock' if "pushback" is expected (BC) (issue4596) If the client allows "pushback", the bundle2 served back by the server may contains parts that will write to the repository. Such parts may require the 'wlock' (eg: bookmark) so we acquire it in advance to make sure it got acquired before the 'lock'.

annotate: always prepare ancestry context of base fctx (issue4600) This patch extends the workaround introduced by dd01834a696f. Even if the base fctx is the same as intorrev, _ancestrycontext must be built for faster _changeid lookup. repo: https://hg.mozilla.org/releases/mozilla-beta command: hg annotate -r 4954faa47dd0 gfx/thebes/gfxWindowsPlatform.cpp before: 52.450 sec after: 1.820 sec

unbundle: acquire 'wlock' when processing bundle2 (BC) (issue4596) A bundle2 may contain bookmark updates (or other extension content) that requires the 'wlock' to be written. As 'wlock' must be acquired before 'lock', we must stay on the side of caution and use both in all case to ensure their ordering.

run-test: enable the devel warning during tests This should help us to catch new locking order issues as soon as possible. There are two harmless test updates (from the config change). Moreover, some bundle2 tests are displaying warning for a legitimate reason. The use of pushkey during the unbundle process may requires the 'wlock' after 'lock' (around the whole unbundle process was taken). This is non-trivial to fix, so I better have the check on, with the warning in the test than the check off. See issue4596 for details.

wlock: do not warn for non-wait locking We are warning about lock acquired in the wrong order because this can create dead-lock situation. But non-wait acquisition will not block and therefore not create a dead-lock. So we do not need to wait in such case.

develwarn: include call site in the simple message version Just displaying the warning makes it quite hard to recognise the guilty code quickly and using --traceback for all calls is not very convenient. So we include the call site with all simple message to help developer to recognise errors sources.