stack: use self._revs in stack.heads() No code cares about the ordering of the heads anyway, so let's use the unordered property that doesn't need to be sliced (because it doesn't include base).

pick: Add a test to check that pick pick the right content

WIP on handling stacks

test: add a test for current behavior of precursors revset The precursors revset currently returns the closest predecessors of a revset. If these predecessors are not known locally, it returns an empty list.

obshistory: give a more correct name to a variable This variable holds a list of predecessors, which obslog presents to graphmod as parents so the latter could understand the data without the need to introduce another graph edge type specifically for predecessors. Also remove debug comments.

tests: unindent lines that only have one leading space One space is not even defined in our .t files syntax.