stream-clone: factor computation of requirement of a stream clone This gather code duplicated in multiple place and will make it easier to modify it safely in the future. Differential Revision: https://phab.mercurial-scm.org/D12028

stream-clone: factor computation of new clone requirement out This gather code duplicated in multiple place and will make it easier to modify it safely in the future. Differential Revision: https://phab.mercurial-scm.org/D12027

stream-clone: drop some outdated lines in test-stream-bundle-v2.t These line refer to a "dirstate-v2" variant that is no longer in use. The associated line drifted out of sync with reality. Differential Revision: https://phab.mercurial-scm.org/D12026

relnotes: add note about changed labels texts Differential Revision: https://phab.mercurial-scm.org/D12085

graft: attempt to make merge labels more helpful Differential Revision: https://phab.mercurial-scm.org/D12025

shelve: attempt to make merge labels more helpful Differential Revision: https://phab.mercurial-scm.org/D12024

histedit: attempt to make merge labels more helpful Differential Revision: https://phab.mercurial-scm.org/D12023

update: set custom conflict label for base commit Differential Revision: https://phab.mercurial-scm.org/D12022

merge: set custom conflict label for base commit Differential Revision: https://phab.mercurial-scm.org/D12021

rebase: set custom conflict label for base commit Differential Revision: https://phab.mercurial-scm.org/D12020

simplemerge: take over formatting of label from `filemerge` The padding we do of conflict labels depends on which conflict marker style is used. For two-way conflict markers (the default), the length of the base label shouldn't matter. It does before this patch, however. This patch moves the formatting from `filemerge` to `simplemerge`. The latter knows which conflict marker style to use, so it can easily decide about the padding. This change will allow us to use more descriptive "base" labels without causing illogical padding in 2-way markers. I'll do that next. One wrinkle is that we pass the same labels to external merge tools. I decided to change that in this patch to be simpler: no padding, and no ellipsis to fit within 80 columns. My reasoning is that the typical external, 3-or-4-panel merge tool doesn't show the labels on top of each others, so the padding doesn't make sense there. The ellipsis is probably not necessary because the external tools probably have their own way of dealing with long labels. Also, we limit them to "80 - 8" to fit the "<<<<<<< " before, which is almost definitely not what an external tool would put there. Differential Revision: https://phab.mercurial-scm.org/D12019

filemerge: pass `simplemerge.MergeInput` to tool functions Differential Revision: https://phab.mercurial-scm.org/D12018

filemerge: work with `simplemerge.MergeInput` in `filemerge()` We currently pass around pairs of file context objects and labels between functions in the `filemerge` module. I plan to pass around `simplemerge.MergeInput` instead. This patch prepares for that by using the type internally in `filemerge.filemerge()`. Differential Revision: https://phab.mercurial-scm.org/D12017

filemerge: always define a "base" label It simplifies the code and improves the conflict markers to always have the "base" label defined. Differential Revision: https://phab.mercurial-scm.org/D12016