rebase: fix bug where `--collapse` would apply diff on missing file Even though the file was missing, the rebase would succeed. Differential Revision: https://phab.mercurial-scm.org/D7897

rebase: extract a variable for a repeated `repo[p1]` I'll add another use site in the next patch. Differential Revision: https://phab.mercurial-scm.org/D7896

graftcopies: document why the function is useful at all Despite having spent a significant amount on time on the copy-tracing code, I thought `graftcopies()` (formerly known as `duplicatecopies()`) was needed to duplicate copies after calling `merge.update()` to do a merge (as `merge.graft()` does), but it's actually usually not needed; `merge.update()` takes care of most copies. This patch documents what the function is for. Differential Revision: https://phab.mercurial-scm.org/D7861

graftcopies: remove `skip` and `repo` arguments The `skip` argument was added in 2ba6c9b4e0eb (rebase: fix bug that caused transitive copy records to disappear (issue4192), 2014-06-07) in order to fix https://bz.mercurial-scm.org/show_bug.cgi?id=4192. I ran tests at that commit without the `skiprev` argument and the only difference I noticed was that `test-rebase-collapse.t` failed differently, in the call that is now on line 501. Without the `skiprev` argument, that call would end up creating another commit because it tried to record an invalid copy. With the previous patch in this series, such invalid copies are no longer recorded, so it seems we don't need the `skip` argument anymore. I also removed the `repo` argument since that also becomes unused with the removal of the `skip` argument. Differential Revision: https://phab.mercurial-scm.org/D7860