revset: made addset a private class This class is not supposed to be used outside revset.py since it only wraps content that is used by baseset typed classes. It only gets created by revset operations or private methods.

revset: made descgeneratorset a private class This class is not supposed to be used outside revset.py since it only wraps content that is used by baseset typed classes. It only gets created by revset operations or private methods.

revset: made ascgeneratorset a private class This class is not supposed to be used outside revset.py since it only wraps content that is used by baseset typed classes. It only gets created by revset operations or private methods.

revset: made generatorset a private class This class are not supposed to be used outside revset.py since it only wraps content that is used by baseset typed classes. It only gets created by revset operations or private methods.

cmdutil: changed walkchangerevs to use spanset instead of baseset Using a spanset takes almost no memory at all. A baseset builds the entire list in memory and is much slower for methods like __contains__.

revset: added sort methods to generatorsets Method needed to propagate sort calls amongst lazy structures. The generated list (stored in the object) is sorted. If the generated list did not contain all elements from the generator, we take care of that before sorting the list.

merge with stable

fix_bytesmod: use the "from mercurial" form of the import to avoid breaking httpclient Without this patch, 2to3's rewrites to httpclient cause it to fail to import. With this patch, it's probably hopelessly broken, but at least won't block forward progress on non-http2 functionality on Python 3.

commit: create new amend changeset as secret correctly for "--secret" option Before this patch, "hg commit --amend --secret" doesn't create new amend changeset as secret, even though the internal function "commitfunc()" passed to "cmdutil.amend()" make "phases.new-commit" configuration as "secret" temporarily. "cmdutil.amend()" uses specified "commitfunc" only for temporary amend commit, and creates the final amend commit changeset by "localrepository.commitctx()" directly with memctx. This patch creates new amend changeset as secret correctly for "--secret" option, by changing "phases.new-commit" configuration temporarily before "localrepository.commitctx()".

hg log: solves bug regarding hg log -r 0:null (issue4039) 'hg log -r 0:null' was showing only one changeset(the '-1' one) instead of the first two changesets.