merge: use the new action based mapping introduced in mergeresult obj
Before this patch, we have good number of instances of following types:
```
for f, (m, args, msg) in mresult.actions:
if m == ACTION_X:
do_something
```
We iterate over the whole list and then filter for a certain action. Previous
patch introduced a action based mapping in mergeresult object. The above code
now looks like:
```
for f, args, msg in mresult.getactions([ACTION_X, ...]):
do_something
```
Differential Revision: https://phab.mercurial-scm.org/D8831
$ cat > unix2mac.py <<EOF
> import sys
>
> for path in sys.argv[1:]:
> data = open(path, 'rb').read()
> data = data.replace(b'\n', b'\r')
> open(path, 'wb').write(data)
> EOF
$ hg init
$ echo '[hooks]' >> .hg/hgrc
$ echo 'pretxncommit.cr = python:hgext.win32text.forbidcr' >> .hg/hgrc
$ echo 'pretxnchangegroup.cr = python:hgext.win32text.forbidcr' >> .hg/hgrc
$ cat .hg/hgrc
[hooks]
pretxncommit.cr = python:hgext.win32text.forbidcr
pretxnchangegroup.cr = python:hgext.win32text.forbidcr
$ echo hello > f
$ hg add f
$ hg ci -m 1
$ "$PYTHON" unix2mac.py f
$ hg ci -m 2
attempt to commit or push text file(s) using CR line endings
in dea860dc51ec: f
transaction abort!
rollback completed
abort: pretxncommit.cr hook failed
[255]
$ hg cat f | f --hexdump
0000: 68 65 6c 6c 6f 0a |hello.|
$ f --hexdump f
f:
0000: 68 65 6c 6c 6f 0d |hello.|