merge with stable

help: drop help for branches template keyword The {branches} keyword dates to pre-1.0 Mercurial's tag-like branch scheme which allowed changesets to be on multiple branches. This is the last visible vestige of that scheme, users should instead be using {branch}, possibly with if().

test-command-template.t: fix failure due to trailing whitespace

templater: makes branches work correctly with stringify (issue4108)

manifest: increase lrucache from 3 to 4 During a commit amend there are 4 manifests being handled: - original commit - temporary commit - amended commit - merge base This causes a manifest cache miss which hurts perf on large repos. On a large repo, this fix causes amend to go from 6 seconds to 5.5 seconds.

strip: add faster revlog strip computation The previous revlog strip computation would walk every rev in the revlog, from the bottom to the top. Since we're usually stripping only the top few revs of the revlog, this was needlessly expensive on large repos. The new algorithm walks the exact number of revs that will be stripped, thus making the operation not dependent on the number of revs in the repo. This makes amend on a large repo go from 8.7 seconds to 6 seconds.

revlog: return lazy set from findcommonmissing When computing the commonmissing, it greedily computes the entire set immediately. On a large repo where the majority of history is irrelevant, this causes a significant slow down. Replacing it with a lazy set makes amend go from 11 seconds to 8.7 seconds.

merge with stable

histedit: hold wlock and lock while in progress Currently, histedit acquires and releases lock and wlock several times during its run. This isn't great because it allows other hg processes to come in and change state. With this fix, lock and wlock are acquired and released exactly once. The change to test-histedit-drop.t is a minor implementation one -- the cache is still correctly invalidated, but it just happens a little later and only gets printed out because of the unrelated --debug flag.

merge with i18n