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
$ hg init
$ echo "added file1" > file1
$ echo "added file2" > file2
$ hg add file1 file2
$ hg commit -m "added file1 and file2"
$ echo "changed file1" >> file1
$ hg commit -m "changed file1"
$ hg -q log
1:08a16e8e4408
0:d29c767a4b52
$ hg id
08a16e8e4408 tip
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg id
d29c767a4b52
$ echo "changed file1" >> file1
$ hg id
d29c767a4b52+
$ hg revert --all
reverting file1
$ hg diff
$ hg status
? file1.orig
$ hg id
d29c767a4b52
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo "changed file1" >> file1
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg revert --all
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg revert -r tip --all
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg update -C
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip