copies-rust: rename TimeStampedPathCopy to CopySource Same rational as the previous changesets. CopySource is a clear descriptive name that does not depends on an implementation details that we are about to the change. Differential Revision: https://phab.mercurial-scm.org/D9642

copies-rust: rename TimeStampedPathCopies to InternalPathCopies We are looking into moving away from TimeStampedPathCopy (that use is_ancestors call to detect overwrite) in favor of an approach that does not requires is_ancestors calls. Yet we will still need an internal representation that differs from the returned result. So we call it "InternalPathCopies" which is generic but clear. Differential Revision: https://phab.mercurial-scm.org/D9641

copies: detect case when a merge decision overwrite previous data We now detect and record when a merge case required special logic (eg: thing that append during the merge, ambiguity leading to picking p1 data, etc) and we explicitly mark the result as superseding the previous data. This fixes the family of test we previously added. Differential Revision: https://phab.mercurial-scm.org/D9613

copies: rearrange all value comparison conditional To properly handle the newly tested case (chaining of merges) we will need to detect more accurately when an actualy merging of the copy information (and superseed the two existing data). Before starting to do so, we need to reorganise the values comparison to introduce different conditional branches when such actual merging is needed/detected. To avoid mixing too many change in this complicated code, we do the reorganisation before adding the "overwrite detection" logic in the next changesets. Differential Revision: https://phab.mercurial-scm.org/D9612

test-copies: introduce merge chains test for the P/Q merges This is similar to the chaining test we have for the A/E merges. The current result of this tests is wrong, as for the other test of the same familly. This will be fixed by a later changesets. Differential Revision: https://phab.mercurial-scm.org/D10059

test-copies: add a case involving the `b` and a new `r` branch That case involve a branch overwriting copies information from the other one. It is similar to the `mBFm` / `mFBm` case except this case actual content merge is involved too. Differential Revision: https://phab.mercurial-scm.org/D10058

test-copies: introduce case combining the `p` and `q` branch That case involves conflicting copies information from each branch. It is similar to the `mAEm` / `mEAm` case except this case actual content merge is involved too. Differential Revision: https://phab.mercurial-scm.org/D10057

test-copies: add a `q` branch similar to the `e` but on the new files This branch will be used to create merge case that mirror ones involving the `e` branch. Differential Revision: https://phab.mercurial-scm.org/D10056

test-copies: add a `p` branch similar to the `a` but on the new files This branch will be used to create merge case that mirror ones involving the `a` branch. Differential Revision: https://phab.mercurial-scm.org/D10055

test-copies: move the new files in the `i` branch The initial branch is moving some of the "same content" file around. We do the same for the "different content" before start to implement more tests. The new files have harmless impact of various existing tests. Differential Revision: https://phab.mercurial-scm.org/D10054

test-copies: add 3 new files with their own content The new `p`, `q` and `r` file mirror the `a`, `b` and `h` but with different content for each files. This will be used to create "mirror" test case that involve actual merge happening. For now, we only add the file to keep patches small and easier to review. Differential Revision: https://phab.mercurial-scm.org/D10053

test-copies: introduce merge chaing test for the A/E + change tests This is similar to the chaining test we have for the A/E merges (without change). The current result of this tests is wrong, as for they "without change counter part". This will be fixed by a later changesets. Differential Revision: https://phab.mercurial-scm.org/D10052

test-copies: add a "change during merge" variant to the A+E test Checks inline comment for details.

test-copies: filter out the linkrev part of `debugindex` It is not really useful for the tests and is a large source of churn when adding more revisions to the tests. Differential Revision: https://phab.mercurial-scm.org/D10050

test-copies: use "case-id" instead of revision number when listing sidedata The revision number are not very informative and can change when new changeset are added, creating unnecessary churn. We change the template before adding more test to improve clarify of the over changesets. Differential Revision: https://phab.mercurial-scm.org/D10049

test-copies: remove revision number from log Differential Revision: https://phab.mercurial-scm.org/D10048

test-copies: add test chaining multiple merge Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9611

test-copies: add test chaining multiple merges Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9610

test-copies: add test chaining multiple merges Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9609

test-copies: add subcase titles for various "conflicting" information variant This make the transitions between case clearer. Differential Revision: https://phab.mercurial-scm.org/D10047

test-copies: improve description of the B+F case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10046

test-copies: improve description of the C+H case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10045

test-copies: improve description of the B+C "revert/restore" case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10044

test-copies: improve description of the G+C case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10043

test-copies: improve description of the G+F case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10042

test-copies: improve description of the D+G case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10041

test-copies: improve description of the A+E case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10040

test-copies: improve description of the B+D case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10039

test-copies: improve description of the B+C case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10038

test-copies: improve description of the A+B case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10037