revlog: do not compute node location by hand in index_invalidate_added The node is not guaranteed to be at the same location all the time (e.g: changelog v2), so let's use the official existing API to get that value. Differential Revision: https://phab.mercurial-scm.org/D12176

rank: compute property incrementally This replaces the naive rank computation with a more efficient incremental method, avoiding computing the whole ancestor set when possible. Differential Revision: https://phab.mercurial-scm.org/D12143

rank: add test with golden values This adds a regression test for the computation of the rank, using the current values computed with the naive algorithm as the "golden" reference. Differential Revision: https://phab.mercurial-scm.org/D12142

rank: add minimal test This adds a small test checking the rank computation in the case of a merge. Differential Revision: https://phab.mercurial-scm.org/D12141

rank: add context and template keyword This makes the stored rank property accessible, to be expanded and printed. Differential Revision: https://phab.mercurial-scm.org/D12140

rank: naive rank property computation and retrieval This stores the rank (size of the ancestor set of a revision, including itself) in a changelog field and allows this property to be retrieved. This new property is used as part of stable-range computations, which will be introduced later on. The value is computed in a naive way from the definition of the rank. This will be replaced by a more efficient version subsequently. Differential Revision: https://phab.mercurial-scm.org/D12139

filemerge: move check for identical sides out of filemerge() `filemerge.filemerge()` returns `None` if no merge was necessary because the two sides were identical. I don't think it should be that function's responsibility to handle that case; we should ideally not even call `filemerge.filemerge()` if the two inputs identical. This patch therefore moves the check out to the caller (`mergestate.py`). The largefiles test changed because we now notice that the two sides made the same change, so we don't consider it a merge. Also note that the new message better matches the line above it in the test output. Differential Revision: https://phab.mercurial-scm.org/D12154

mergestate: use an early return for trivial merges `filemerge.filemerge()` returns `None` if no merge was needed because the two sides were identical. I'd like to move that to the caller. This is a little refactoring to prepare for that. Differential Revision: https://phab.mercurial-scm.org/D12153

simplemerge: remove now-unused arguments The `ui` argument is no longer needed now that we don't handle `--print` in the library code. Differential Revision: https://phab.mercurial-scm.org/D12151

merge: fix documented order of `labels` argument Differential Revision: https://phab.mercurial-scm.org/D12150