evolve: add logic to handle a particular case in divergence resolution Case is: In content divergence, to check if the two csets are on different parent or same parent what we do is find gca of the two csets and then compare it with the singlesuccessors of two csets's parents. Now, if gca is same as singlesuccessors of both the csets then we conclude that both are on the same parent which is not totally correct as it is possible that both the parents of two csets are obsolete with a single successor. This patch adds the logic to cover the above metioned case correctly, deciding the part when we need to relocate a cset to other side while resolving the stack of divergent csets. Changes in test file demonstrate that before this patch we were not doing it right because it should have relocated every node to other side instead of just relocating the first one from the stack.

evolve: add a test reflecting wrong behaviour of content-div resolution This patch shows that currently the case when stack of divergent csets have different parents is not handled correctly. For a stack of csets which has different parent, right behaviour is to relocate every node before performing merge but present implementation only relocate first cset in the stack and skip relocation for the rest of csets, this is not what we expect it to do. Next patch will be about fixing this issue.

compat: add support for new arg name in memfilectx.__init__ This makes us compatible with 550a172a603b (memctx: rename constructor argument "copied" to "copysource" (API), 2019-03-19).

evolve: preserve compatibility for hg < 4.8 versions This patch make sure evolve don't break if user using a version of hg before this 7694b685bb10 patch on hg-committed.

evolve: warn user if cset desc is being lost In public divergence when merging results in same as public cset, we only create markers to solve the divergence i.e. [(public, (other,))] In this case if other cset had a desc which was different from public that will be lost. So this print out a warning message to user that desc of non-public cset is being lost. Changes in test files reflect the added behaviour.

changelog: mention latest improvement

stack: make @ (current) more important than $ (some sort of unstable) Base is still ^ even if it's currently checked out.

stack: show content and phase divergent state and symbol Replacing ' ' with '-' is just for color labels.

stack: handle external-children just like other states This also fixes color labels: previously when external-children was combined with another state, --color=debug would show something like: [topic.stack.index topic.stack.index.current - external-children|s4] Now there is a separate label for each state.

stack: optimize revset used for stack --children Since that option needs to exclude changesets on the current stack, let's just use stack.revs (that are cached) for that and skip branch() or topic() revset. st.revs[0] is the stack base, we don't consider it actual part of stack.