test-compat: merge mercurial-4.5 into mercurial-4.4

test-compat: merge mercurial-4.6 into mercurial-4.5

test-compat: merge stable into mercurial-4.6

branching: merge stable into default

caches: issue both debug and blackbox log message This increase the odd someone looking for issue will find them.

cmdrewrite: rename variable and move it closer to where it is used Renaming to satisfy pep8-naming linter plugin, which complained on this variable because all-uppercase names are reserved for constants, and constants need to be module-level. This variable is not a good choice for moving up to the module level because it's used only in one place. Additionally, let's have it closer to the place it's actually used to potentially avoid an extra call to _() function (however cheap it may be).

changelog: mention the cache improvements

obshashrangecache: be more paranoid in the errors we catch It seems like there error were already covered. Better safe than sorry.

stablerangecache: be more paranoid in the errors we catch It seems like there error were already covered. Better safe than sorry.

stablesortcache: update the variable tracking on-disk state after write Since we updated the on disk content, we should update that value. In practice the object will likely be discarded after the write, but there is nothing wrong in being more correct.