view contrib/python-zstandard/LICENSE @ 47372:9e6e12e1a87e

merge: make applyupdates() not mutate mresult argument

We have an extension at work that overrides `merge.applyupdates()` to
make it skip some writes and instead instruct the virtual filesystem
we use to get a different version. That override doesn't work
correctly when doing `hg co -m` and there's a modified file in the
dirstate that's deleted in the destination. That's because
`applyupdates()` mutates its `mresult` argument and our extension had
passed in a modified copied of `mresult` to the overridden function,
which resulted in the mutation not having any effect. This patch fixes
that by letting the caller (i.e. `merge._update()`) update `mresult`
with the extra actions instead. Besides fixing our internal extension,
that seems cleaner to me anyway (better to not mutate `mresult` only
in some cases and we can skip some of the logic if we're not going to
update the dirstate anyway).

Differential Revision: https://phab.mercurial-scm.org/D10830

Copyright (c) 2016, Gregory Szorc
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