repair: move check for existing transaction earlier
Several benefits:
* Gets close the comment describing it
* Splits off unrelated comment about "backup" argument
* Error checking is customarily done early
* If we added an early return to the method, it would still
consistently fail if there was an existing transaction (so
we would find and fix that case quickly)
One test needs updating with for this change, because we no longer
create the backup bundle before we fail. I don't see much reason to
create that backup bundle. If some command was adding content and then
trying to strip it as well within the transaction, we would have a
backup for the user, but the risk of that not being discovered in
development seems very small.
test branch selection options
$ hg init branch
$ cd branch
$ hg branch a
marked working directory as branch a
(branches are permanent and global, did you want a bookmark?)
$ echo a > foo
$ hg ci -d '0 0' -Ama
adding foo
$ echo a2 > foo
$ hg ci -d '0 0' -ma2
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch c
marked working directory as branch c
$ echo c > foo
$ hg ci -d '0 0' -mc
$ hg tag -l z
$ cd ..
$ hg clone -r 0 branch branch2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd branch2
$ hg up 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch b
marked working directory as branch b
$ echo b > foo
$ hg ci -d '0 0' -mb
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 branch æ
marked working directory as branch \xc3\xa6 (esc)
$ echo ae1 > foo
$ hg ci -d '0 0' -mae1
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 branch -f æ
marked working directory as branch \xc3\xa6 (esc)
$ echo ae2 > foo
$ hg ci -d '0 0' -mae2
created new head
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch -f b
marked working directory as branch b
$ echo b2 > foo
$ hg ci -d '0 0' -mb2
created new head
unknown branch and fallback
$ hg in -qbz
abort: unknown branch 'z'!
[255]
$ hg in -q ../branch#z
2:f25d57ab0566
$ hg out -qbz
abort: unknown branch 'z'!
[255]
in rev c branch a
$ hg in -qr c ../branch#a
1:dd6e60a716c6
2:f25d57ab0566
$ hg in -qr c -b a
1:dd6e60a716c6
2:f25d57ab0566
out branch .
$ hg out -q ../branch#.
1:b84708d77ab7
4:65511d0e2b55
$ hg out -q -b .
1:b84708d77ab7
4:65511d0e2b55
out branch . non-ascii
$ hg --encoding utf-8 up æ
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding latin1 out -q ../branch#.
2:df5a44224d4e
3:4f4a5125ca10
$ hg --encoding latin1 out -q -b .
2:df5a44224d4e
3:4f4a5125ca10
clone branch b
$ cd ..
$ hg clone branch2#b branch3
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files (+1 heads)
updating to branch b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -q -R branch3 heads b
2:65511d0e2b55
1:b84708d77ab7
$ hg -q -R branch3 parents
2:65511d0e2b55
$ rm -rf branch3
clone rev a branch b
$ hg clone -r a branch2#b branch3
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files (+1 heads)
updating to branch a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -q -R branch3 heads b
2:65511d0e2b55
1:b84708d77ab7
$ hg -q -R branch3 parents
0:5b65ba7c951d
$ rm -rf branch3