evolve: introduce function to create a obsmarker relation even for public cset To create obsmarkers we use obsolete.createmarkers() function, but because of security reasons this function refuses to create obsmarkers for public cset. And we need to create obsmarkers for a public cset while solving public content divergence. So introducing this function which create a obsmarker relation even for immutable cset. Currently this function create obsmarker for a single relation, in contrast of obsolete.createmarkers() which create markers for multiple relations. Upcoming pathces will be using this function.

topic: make ranges work in revset relations like 'foo#stack[1:2]'

topic: simplify #stack index check/access Also using stack.revs instead of list(stack). It's equivalent and stack.revs is @propertycache'd.

topic: make ranges work in revset relations like 'foo#topic[1:2]' Since #topic is very similar to #generations, we reuse the function directly. Few tests because #generations is already tested in core.

evolve: add description of function solveobswdp

evolve: document the "if not shouldupdate" block I missed the "not" in "if not shouldupdate: ... hg.updaterepo()" and it took a long time for me to realize it's about updating *back* to the original commit (or to its successor). Let's add a comment to maybe help the person not make the same mistake.

evolve: make "startnode" consistently be a node, not a context This fixes a bug where we didn't print "working directory is not at ..." after `hg evolve --continue` because we were comparing a node and a context.

evolve: use context managers for locks and transaction