contrib: don't hardcode path to bash interpreter Use the env binary to figure out the correct bash to use. Certain systems ships with an ancient version of bash, but the user might have installed a newer one that is earlier in $PATH. For example the current version of Mac OS X ships version 3.2.51 of bash, which does not understand new fancy builtins such as readarray. A user might install a newer version of bash, use that as their shell and add that path before bin.

contrib: explicitly enable perf extension for revset tests If a developer doesn't have the perf extension enabled the revset benchmarking will fail. This patch explicitly enables the perf extension when running the tests.

merge with stable

revset: improve performance of _generatorset.__contains__ (issue 4201) _generatorset.__contains__ and __contains__ from child classes were calling into __iter__ to look for values. Since all previously-encountered values from the generator were cached and checked in __contains__ before this iteration, __contains__ was effectively performing iteration busy work which could lead to an explosion of redundant work. This patch changes __contains__ to be more intelligent. Instead of looking at all values via __iter__, __contains__ will instead go straight to "new" values from the underlying generator. On a clone of the Firefox repository with around 200,000 changesets, this patch decreases the execution time of the revset '::(200067)::' from ~100s to ~4s on the author's machine. Rebase operations (which use the aforementioned revset), speed up accordingly.