mq: factor out push conditions checks
Some extensions (e.g. hgsubversion) completely override push command. Because
extensions load order is unspecified, if hgsubversion loads before mq, mq
checks about not pushing applied patches will be bypassed. Short of finding a
way to fix load order, extracting the checking logic will allow
hgsubversion-like extensions to run the check themselves.
$ hg init a
$ cd a
$ echo a > a
$ hg add -n
adding a
$ hg st
? a
$ hg add
adding a
$ hg st
A a
$ hg forget a
$ hg add
adding a
$ hg st
A a
$ echo b > b
$ hg add -n b
$ hg st
A a
? b
$ hg add b
$ hg st
A a
A b
should fail
$ hg add b
b already tracked!
$ hg st
A a
A b
$ hg ci -m 0 --traceback
should fail
$ hg add a
a already tracked!
$ echo aa > a
$ hg ci -m 1
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo aaa > a
$ hg ci -m 2
created new head
$ hg merge
merging a
warning: conflicts during merge.
merging a failed!
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg st
M a
? a.orig
should fail
$ hg add a
a already tracked!
$ hg st
M a
? a.orig
$ hg resolve -m a
$ hg ci -m merge
Issue683: peculiarity with hg revert of an removed then added file
$ hg forget a
$ hg add a
$ hg st
? a.orig
$ hg rm a
$ hg st
R a
? a.orig
$ echo a > a
$ hg add a
$ hg st
M a
? a.orig
$ hg add c && echo "unexpected addition of missing file"
c: No such file or directory
[1]
$ echo c > c
$ hg add d c && echo "unexpected addition of missing file"
d: No such file or directory
[1]
$ hg st
M a
A c
? a.orig