context: avoid writing outdated dirstate out (
issue5584)
Before this patch, workingctx.status() may cause writing outdated
dirstate out, if:
- .hg/dirstate is changed simultaneously after last loading it,
- there is any file, which should be dirstate.normal()-ed
Typical issue case is:
- the working directory is updated by "hg update"
- .hg/dirstate is updated in background (e.g. fsmonitor)
This patch compares identities of dirstate before and after
acquisition of wlock, and avoids writing outdated dirstate out, if
change of .hg/dirstate is detected.