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
--- a/mercurial/merge.py Thu Jun 03 16:12:03 2021 +0200
+++ b/mercurial/merge.py Tue Jun 01 15:19:08 2021 -0700
@@ -1724,20 +1724,13 @@
removed += msremoved
extraactions = ms.actions()
- if extraactions:
- for k, acts in pycompat.iteritems(extraactions):
- for a in acts:
- mresult.addfile(a[0], k, *a[1:])
- if k == mergestatemod.ACTION_GET and wantfiledata:
- # no filedata until mergestate is updated to provide it
- for a in acts:
- getfiledata[a[0]] = None
progress.complete()
- assert len(getfiledata) == (
- mresult.len((mergestatemod.ACTION_GET,)) if wantfiledata else 0
+ return (
+ updateresult(updated, merged, removed, unresolved),
+ getfiledata,
+ extraactions,
)
- return updateresult(updated, merged, removed, unresolved), getfiledata
def _advertisefsmonitor(repo, num_gets, p1node):
@@ -2122,7 +2115,7 @@
)
wantfiledata = updatedirstate and not branchmerge
- stats, getfiledata = applyupdates(
+ stats, getfiledata, extraactions = applyupdates(
repo,
mresult,
wc,
@@ -2133,6 +2126,18 @@
)
if updatedirstate:
+ if extraactions:
+ for k, acts in pycompat.iteritems(extraactions):
+ for a in acts:
+ mresult.addfile(a[0], k, *a[1:])
+ if k == mergestatemod.ACTION_GET and wantfiledata:
+ # no filedata until mergestate is updated to provide it
+ for a in acts:
+ getfiledata[a[0]] = None
+
+ assert len(getfiledata) == (
+ mresult.len((mergestatemod.ACTION_GET,)) if wantfiledata else 0
+ )
with repo.dirstate.parentchange():
repo.setparents(fp1, fp2)
mergestatemod.recordupdates(