tests/test-status-inprocess.py.out

annotate: reuse already calculated annotation

Before this patch, annotation is re-calculated even if it is already
calculated. This may cause unexpected annotation, because already
cleared "pcache" ("pcache[f] = []") prevents from scanning ancestors.

This patch reuses already calculated annotation if it is available.

In fact, "reusable" situation should be seen only on legacy
repositories in which a filelog include the merging between the
revision and its ancestor, because:

  - tree is scanned in depth-first

    without such merging, annotation result should be released soon

  - recent Mercurial doesn't allow such merging

    changelog and manifest can include such merging someway, but
    filelogs can't, because "localrepository._filecommit()" converts
    such merging request to linear history.

% creating repo
% add and commit
C test.py
% change
M test.py