tags: don't read .hgtags fnodes from tags cache files Now that we have a standalone and shared cache for .hgtags fnodes, the .hgtags fnodes stored in the tags cache files are redundant. Upcoming patches will change the format of the tags cache files to remove this data and to improve the validation. To prepare for this, we change the tags reading code to ignore all but the tip .hgtags fnodes entries in existing tags cache files. All fnodes lookups now go through our new shared cache, which is why test output changed. Format of tags cache files has not yet changed.

rebase: restore bookmark state on abort The bookmark state was already being preserved, but it wasn't being properly restored.

histedit: store backup file before histedit It's possible for the user to delete some of the commits they started with during a histedit, and aborting the histedit doesn't bring them back. Let's store a backup bundle so we can always recover the stack of commits from before they began.

histedit: replace pickle with custom serialization Pickle is undesirable, so let's serialize it ourselves. We keep the ability to parse existing pickle blobs for now.

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.