tests: add some more actions to test-issue-6028, describe what's being done This patch does two things: it explains what's happening in the test file so it's easier to understand, and also it adds checks that make sure something like swapping merge parents is not accidentally breaking anything. The primary reason to touch this test file was that it was broken by a change in core's merge.graft() that erroneously swapped merge parents. Since only evolve uses merge.graft() for merge commits and there aren't any tests in core for it, let's test it here. Plus, this test case is pretty simple and these additional checks don't make it too complicated.

topic: fix some API to make it more robust The new code can deal with changes in upstream mercurial.

rewriteutil: move allowdivergence check to foldcheck() foldcheck() calls precheck() first and then performs more fold-specific checks.

test: change to output around transaction timing CORE-TEST-OUTPUT-UPDATE: d7304434390f

branching: merge with stable There have been multiple fix on stable.

stablerange: add some data from field testing This show that in number of stable range to track stay reasonable.

stablerange: add a debugstablerangecache command The command display get some data about stable range in a repository.

stablerange: add some documentation about the general concept

stablesort: add some field data about stable sort cache

stablesort: introduce a small debugstablesortcache command This give a small insight on the cache content.