copies: filter invalid copies only at end of pathcopies() (issue6163) copies._filter() filters out copies whose source file does not exist in the start commit or whose target file does not exist in the end commit. We do that after chaining copies with dirstate copies or backward renames from another branch. We also do at the end of the changeset-centric copy tracing. The filtering means that we will remove copies to/from files that did not exist in some intermediate commit. That is inconsistent with what we do if a file has been deleted and then re-added (we allow updating across that). Copying the two first examples from issue6163: @ 4 'rename x to y' | o 3 'add x again' | o 2 'remove x' | | o 1 'modify x' |/ o 0 'add x' @ 4 'rename x to y' | o 3 'add x again' | | o 2 'modify x' | | | o 1 'add x' |/ o 0 'base' When doing `hg rebase -r 1 -d 4` in the first case, it succeeds, but `hg rebase -r 2 -d 4` in the second case does not. That's because we chain and filter via commit 0, which does not have file 'x' in the second case. IMO, that's clearly inconsistent. So this patch removes the filtering step so it only happens at the end. If a file was temporarily removed, whether via a merge base or not, it will now still be considered the same file. That fixes issue6163 for the changeset-centric case. Differential Revision: https://phab.mercurial-scm.org/D6603

copies: inline _chainandfilter() to prepare for next patch Differential Revision: https://phab.mercurial-scm.org/D6602

copies: remove most early returns from pathcopies() and _forwardcopies() I want to split up _chainandfilter() more so the call to _filter() consistently happens at the end of pathcopies(). This prepares for that change. Differential Revision: https://phab.mercurial-scm.org/D6601

copies: move short-circuiting of dirstate copies out of _forwardcopies() I'd like to move the filtering of copies we do after chaining to the end of all chaining (in a single place in pathcopies()). One problem that came up when trying that was that we allow things like `hg cp -f <file> <existing file>` so the user can later amend that in. Filtering at the end would mean that we remove those copies. That would break `hg st -C`. This patch therefore moves the short-circuiting of dirstate copies into pathcopies() so we can more easily handle the dirstate-only case differently. I initially thought this might change some behavior when the user does `hg status --rev 'wdir()' --rev .` during an uncommitted merge, since _backwardrenames() would reverse the copies in that case. However, I couldn't come up with a test case where it made a difference. Differential Revision: https://phab.mercurial-scm.org/D6600

tests: add more tests of copy tracing with removed and re-added files We had a test where the destination of a copy was removed and then added back. This patch adds similar cases where the break in history instead happens to the source file. There are three versions of this: 1. The break happens before the rename. 2. The break happens on a branch parallel to the rename (where copy tracing is done via the merge base) 3. The source is added on each side of the merge base. The break in history is thus in the form of a deletion when going backwards to the merge base and the re-add happens on the other branch. I've also added calls to `hg graft` in these cases to show the breakage in issue 6163. Another factor in these cases is matching nodeid (checked in copies._tracefile()). I've made two copies each of the cases to show the impact of that. One of these is the same as a test in test-rename-merge1.t, so I also deleted that test from there. Some of these tests currently fail, where "fail" is based on my current thinking of how things should work. I had initially thought that we should be more strict about not tracing copies across commits where the file did not exist, but issue 6163 made me reconsider. The only test case here that behaved differently in 4.9 is the exact case reported in issue 6163. Differential Revision: https://phab.mercurial-scm.org/D6599

tests: split out tests for unrelated copy source/target into separate file I've realized only recently how many cases there are where a file is treated differently if it's considered "related" to another file (not deleted and re-added). I'll add more tests for some of these cases soon. Differential Revision: https://phab.mercurial-scm.org/D6598

subrepos: make last line of prompts <40 english chars (issue6158) Differential Revision: https://phab.mercurial-scm.org/D6572

largefiles: make last line of prompts <40 english chars (issue6158) Differential Revision: https://phab.mercurial-scm.org/D6571

rust-dirstate: add helper to iterate ancestor paths This is modeled after std::path::Path::ancestors(). find_dirs(b"") yields b"" because Mercurial's util.finddirs() works in that way, and the test case for DirsMultiset expects such behavior.

tests: update test-commit-interactive.t for no-execbit platforms These changes correspond with f802a75da585. Differential Revision: https://phab.mercurial-scm.org/D6624