compat: adapt to the new destspace argument of destmerge The argument is currently ignored in the topic case for simplicity, but we properly accept it and propagate it to the original function to prevent crash and behavior regression in the non-topic case.

stack: prevent crash when topic is rooted on nullid We exclude null from displayed base. This was causing a crash when trying to display its description (we'll still have to handle the empty description case, but it is now less urgent).

test: add topic on the first 2 changesets too This will be used to add a test for topic rooted on nullid. We introduce this in its own changeset to reduce the noise if the actual changeset.

test: remove comment about new head warning The new head warning was buggy. This was fixed in bdc5bb223b50.

stack: also change the indexing of the t# reference Changeset 61f36480740f changed the index displayed (we now index from 1), but forgot to update the logic used to resolve the 't#' name. This changeset fixes it.

stack: change the ascii symbold for base Now that the children line go upward, '_' is no longer clear as is take the lower part of the line. We go for '^' that use the upper part.

stack: reverse the display order Most mercurial command display the most recent changeset first. We put `hg topic --list` inline with this.

topic: extract display from entry computation We are about to reverse the order of the output (most recent first) so it will be useful.

stack: start indexing at 't1' instead of 't0' I think 't0' could have special meaning (eg: before 't1', but still with topic activated) so let's keep room for that. Indexing from 1 is not crazy anyway.

commit: wrap "commitstatus" to take topic into account The "created new head" message was appearing for every single commit made on a topic. It should now properly only appears when a new head is actually created on a topic.

uisetup: add call to 'topicmap.modsetup' this was forgotten in 99c1a26abf3f. Tests did not broke because the wrapping of cg.apply only have performance impact (cache warmup).

uisetup: move all remaining wrapping into uisetup All our wrapping is now properly done at uisetup time. Hooray.

topicmap: move 'cgapply' wrapping into the topicmap module More gathering of related logic.

topicmap: move the 'usetopicmap' context manager into the topicmap module There is no good reason to not have it gathered with the rest.