tests: test that narrow preserves bookmarks on widen When widening inserts older commits in the changelog, we have to preserve bookmarks so they are not removed by the call to repair.strip() we temporarily do. We didn't have any tests for that before. Differential Revision: https://phab.mercurial-scm.org/D5396

rebase: clarify that commits that become empty are skipped Our message just said that it created no changes, but we didn't explicitly say that that meant that the the commit was not rebased. It also wasn't clear why it created no changes, so this patch also clarifies that that was because the changes were already in the destination. Differential Revision: https://phab.mercurial-scm.org/D5395

rebase: format commit in usual way when explaining that it became empty We use the _ctxdesc() for other similar messages, so it seems we should use it here too. Differential Revision: https://phab.mercurial-scm.org/D5394

rust: propagate error of index_get_parents() properly Before, rustla_contains() would return 0 on error, and the exception would be cleared or noticed somewhere else. We need to propagate the error from AncestorsIterator up to the FFI surface.

rust: look up HgRevlogIndex_GetParents() from symbol table And removes the unused index_get_parents_checked() function. I expect the Index struct will be turned into a pyobject type, though I haven't written any PoC-level patches yet.

revlog: add public CPython function to get parent revisions Since this is a public function, it validates the input revision, and supports nullrev. index_get_parents_checked() will be replaced by this function.

revlog: rename indexType to HgRevlogIndex_Type as it's a global symbol It follows the CPython naming convention, but uses Hg instead of Py.