tests: remove "second diverged revision" from a phase divergence test It was basically testing the same thing twice with a different comment.

obshistory: omit duplicate notes of obsolescence operations When folding changesets, it's possible to provide a --note flag to e.g. fold or prune, which will store a note for that operation. But since there would be more than one marker for the fold operation and the provided note would be stored in all of them, _markersnotes() previously would return the same text message many times. We don't really want to see the same thing over and over, so let's make notes a set(). This will also make unrelated operations with the same note show the message only once, which is probably an improvement too.

changelog: adjust The changes only apply to newly created sqlite database. There are code pathes that drop existing ones, but that's a more complicated condition.

changelog: mention the sqlite fix

evolve: extract function for relocating divergent commit There was some duplication here, so let's extract to a function. I'm going to add a little bit more shared code next.

caches: preserve permissions of top-level .hg When using hg on a shared filesystem on UNIX, cache files normally inherit the permissions of the .hg directory. This is most commonly used to ensure everything is writable by all users. The sqlite3 cache files don't have a way to directly set the permission, so check if a special mode is necessary and try to apply them to newly created database files.

changelog: mention obsorigin template keyword

templatekw: add obsorigin keyword

obshistory: add predecessorsandmarkers()

obshistory: add a function to group predsets by fold-id

obshistory: add _predecessorsverb() similar to _successorsetverb()

obshistory: add a docstring to patchavailable()

tests: avoid referring to commits by hash in a few places This patch means that the next patch can be written without manual editing of the test cases.

tests: add more verification of output to divergence tests It's not obvious what the obsmarkers should look like in these tests and adding them highlights a bug that happens when commit we create to resolve the divergence doesn't get created because it would be empty. I also added a few graphlog calls to check that the divergence-resolution commit is in the right place (has right parentage).

tests: add debugobsolete calls before many obslog calls As requested by Pierre-Yves. The main reason is to catch superfluous creation of obsmarkers, as well as any future changes to how the obsmarkers get created.