annotate: reuse ancestry context when adjusting linkrev (issue4532) The linkrev adjustment will likely do the same ancestry walking multiple time so we already have an optional mechanism to take advantage of this. Since 2896f53509a7, linkrev adjustment was done lazily to prevent too bad performance impact on rename computation. However, this laziness created a quadratic situation in 'annotate'. Mercurial repo: hg annotate mercurial/commands.py before: 8.090 after: 36.300 Mozilla repo: hg annotate layout/generic/nsTextFrame.cpp before: 1.190 after: 290.230 So we setup sharing of the ancestry context in the annotate case too. Linkrev adjustment still have an impact but it a much more sensible one. Mercurial repo: hg annotate mercurial/commands.py before: 36.300 after: 10.230 Mozilla repo: hg annotate layout/generic/nsTextFrame.cpp before: 290.230 after: 5.560