context: clarify that only one attempt is made to interpret changeid We can now tell what type of revision specifier we have just by looking at it (we no longer attempt to interpret it in one way after the other -- that's now in scmutil.revsymbol()). Let's clarify this in the code by swithing to if/elif. Differential Revision: https://phab.mercurial-scm.org/D3451

context: only bother looking for broken dirstate for 20-byte changeid If we fail to look up a changeid in changectx.__init__, we check if it exactly matches any of the dirstate parents, and if it does, we print a more specific message ("working directory has unknown parent '...'!" instead of "unknown revision '...'"). The dirstate parents are always 20 bytes, so there's no need to check for a match when the given changeid is not 20 bytes. (And now that all the other allowed forms of changeid have been moved out of the constructor, there's no risk that a changeid that did match a dirstate parent was actually a valid bookmark.) Differential Revision: https://phab.mercurial-scm.org/D3450

context: drop support for looking up context by ambiguous changeid (API) This removes support for using the changectx constructor (and thereby repo[x]) for looking up contexts by a stringified int, a namespace key (e.g. a bookmark), or a partial hex nodeid. This means that e.g. repo[<hex nodeid>] will now fail even if a bookmark with the same name exists (which is a good thing IMO). It also means that doing repo[<non-existent node>] no longer ends up loading namespaces (which was a surprising side-effect of creating of failing to create a context object that I recently ran into while debugging something unrelated to this series). Differential Revision: https://phab.mercurial-scm.org/D3449

tests: pass parent revision as integer to repo[x] in test-context-metadata.t Support for looking up by stringified int is going away. It's already deprecated, but I think I didn't notice this case because the test case pipes through `grep`. Differential Revision: https://phab.mercurial-scm.org/D3448

bookmarks: cache reverse mapping (issue5868) I chose a simpler implementation. If the initial cost of building reverse mapping is significant, we'll have to move it under @propertycache. The nodemap could be a dict of sets, but I think keeping a sorted list is better since each node is likely to have zero/one bookmark. Micro-benchmark with 1001 bookmarks and 1001 revisions: $ for n in `seq 0 1000`; do touch $n; hg book book$n; hg ci -qAm$n; done $ hg bookmarks --time > /dev/null (orig) time: real 0.040 secs (user 0.050+0.000 sys 0.000+0.000) (new) time: real 0.040 secs (user 0.040+0.000 sys 0.010+0.000) $ hg log -T '{bookmarks}\n' --time > /dev/null (orig) time: real 0.160 secs (user 0.160+0.000 sys 0.000+0.000) (new) time: real 0.090 secs (user 0.100+0.000 sys 0.000+0.000)

bookmarks: make argument names of _set/_del() more specific