actions: introduce function to calculate downgrades An upgrade operation can also downgrade/remove some format variants. Before this patch there was no clean way to find out all such variants which will be removed. This patch adds a function for that. It will be used in next patch. Differential Revision: https://phab.mercurial-scm.org/D9618

debugupgraderepo: minor documentation fix When we specify `--no-changelog --no-manifest --no-filelog` we skip all revlog optimization instead of all filelog optimization. Also while I was here, for consistency, I did `optimisation` -> `optimization` to make it consistent with rest of occurrences. Note: I am not native speaker and I only changed it because of consistency. I don't know which one is correct. Differential Revision: https://phab.mercurial-scm.org/D9617

upgrade: rename actions to upgrade_actions The `actions` were a list of optimizations and format upgrades which will be upgraded. This does not include things which will be downgraded. Let's rename the variable for clarity. It now makes obvious that we don't have any concrete information on what things are downgraded. Differential Revision: https://phab.mercurial-scm.org/D9616

upgrade: move optimization addition to determineactions() The documentation of `determineactions()` mention that it is given a list returned from `findoptimizations()` however it was not true before this patch. The code extending actions with optimizations also mentioned about it that this should be in determineactions. So let's do what comments at couple of places say. Differential Revision: https://phab.mercurial-scm.org/D9615

upgrade: drop support for old style optimization names Old style optimization names like `redeltaparent` were converted into `re-delta-parent` more than two years ago. The old names were kept around for sometime because of BC reasons. Refer 5608b5a6c3231c4ec771171cc3079142c7672be6. The commit states the map is there for a while and we can drop them as the underlying command is a debug command. Differential Revision: https://phab.mercurial-scm.org/D9614

upgrade: add a missing space in status message Found while reading the code to refactor. Differential Revision: https://phab.mercurial-scm.org/D9583

actions: rename DEFICIENCY constant to FORMAT_VARIANT It was not obvious what does deficieny means and every format change can't be a deficiency. There are some format changes like compression levels, share-safe which can't be understood at deficiencies. This patch renames the constant to make things clearer. Differential Revision: https://phab.mercurial-scm.org/D9664

upgrade: rename finddeficiences() to find_format_upgrades() It was not obvious what does deficieny means and every format upgrade can't be a deficiency. There are some format upgrades like compression levels, share-safe which can't be understood at deficiencies. A change can be an upgrade or downgrade, however this `finddeficiences()` only used to find upgrades. This patch renames the function and related variables to make things more clearer. The ui message also got improved which is a good thing. Next patch will rename deficiency in general across the upgrade code. Differential Revision: https://phab.mercurial-scm.org/D9582

beautifygraph: change the current commit symbol The existing "circle with vertical fill" character renders as full width in many terminals making the beautified symbols have uneven size. Additionally, the proposed "fisheye" character is the logic 'active' version of the current merge symbol, "bullseye." Differential Revision: https://phab.mercurial-scm.org/D9678

merge with stable