bookmarks: introduce a repo._bookmarks.changectx(mark) method and use it
Many places were doing repo[mark], which usually works, but it's
slightly incorrect: if the bookmark has a name that matches a full hex
nodeid of another node, then the context for the other node will be
returned instead. Also, I'm about to remove support for
repo[<namespace thing>] :)
Differential Revision: https://phab.mercurial-scm.org/D3162
https://bz.mercurial-scm.org/612
$ hg init
$ mkdir src
$ echo a > src/a.c
$ hg ci -Ama
adding src/a.c
$ hg mv src source
moving src/a.c to source/a.c
$ hg ci -Ammove
$ hg co -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo new > src/a.c
$ echo compiled > src/a.o
$ hg ci -mupdate
created new head
$ hg status
? src/a.o
$ hg merge
merging src/a.c and source/a.c to source/a.c
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg status
M source/a.c
R src/a.c
? src/a.o