test-compat: backout change to 1e103c7f7663

compat: use older API for older version This API changed in 4.7, we need to adjust.

branching: create mercurial-4.6 branch for updated test output This branch will be used to check for 4.6 compatibility.

builddependencies: extract function for getting successors The code no longer makes a difference between single- and mult-successor cases and just needs a set (or generator, really) of successors to iterate over. Let's extract that into a function.

builddependencies: share code between single- and multi-successor cases The two cases now have more similar structure ("if succ in revs: dependencies[r].add(succ)"), so let's share the code so it doesn't start drifting apart again.

builddependencies: build inverse dict from forward dict It's error-prone to keep "dependencies" and "rdependencies" in sync (we don't do it correctly when there are multiple successors or a node). It's easier to just create "rependencies" from "dependencies" after it's complete.

builddependencies: remove a use of defaultdict I don't see much reason to make "rdependencies" be a defaultdict when "dependencies" is not. It's easy to initialize each entry ourselves.

branching: merge with stable

builddependencies: don't remove found deps when divergence found (issue5946) It seems obviously wrong to not keep any dependencies for a revision that we had already found (for p1) if we run into divergence (from p2). It also happens to fix issue5946 :)

builddependencies: don't add dependency on revision outside input set This was already handled in the single-successor case, but had been missed in the multiple-successors case. Note that there seems to be a copy of builddependencies() in the topics extension. I don't use topics more than I have to, so I'll let someone else fix that code.