filemerge: when not keeping premerge, don't write markers to context
When premerge is enabled (as it is for non-binary inputs by default)
and the markers are not kept, we currently still write it to the
output context and then restore the previous content right after. With
the refactoring in the previous patch, we can easily avoid that step
and instead write the output in the opposite case (i.e. when it's
successful or when the markers are supposed to be kept).
Differential Revision: https://phab.mercurial-scm.org/D12149
$ cat <<EOF >> $HGRCPATH
> [extensions]
> hooklib =
>
> [phases]
> publish = False
> EOF
$ hg init a
$ hg --cwd a debugbuilddag '.:parent.*parent'
$ hg --cwd a log -G
o changeset: 2:fa942426a6fd
| tag: tip
| parent: 0:1ea73414a91b
| user: debugbuilddag
| date: Thu Jan 01 00:00:02 1970 +0000
| summary: r2
|
| o changeset: 1:66f7d451a68b
|/ user: debugbuilddag
| date: Thu Jan 01 00:00:01 1970 +0000
| summary: r1
|
o changeset: 0:1ea73414a91b
tag: parent
user: debugbuilddag
date: Thu Jan 01 00:00:00 1970 +0000
summary: r0
$ hg init b
$ cat <<EOF >> b/.hg/hgrc
> [hooks]
> pretxnclose.reject_new_heads = \
> python:hgext.hooklib.reject_new_heads.hook
> EOF
$ hg --cwd b pull ../a
pulling from ../a
requesting all changes
adding changesets
adding manifests
adding file changes
error: pretxnclose.reject_new_heads hook failed: Changes on branch 'default' resulted in multiple heads
transaction abort!
rollback completed
abort: Changes on branch 'default' resulted in multiple heads
[255]
$ hg --cwd b pull ../a -r 1ea73414a91b
pulling from ../a
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets 1ea73414a91b (1 drafts)
(run 'hg update' to get a working copy)