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.
#require unix-permissions no-root
$ hg init t
$ cd t
$ echo foo > a
$ hg add a
$ hg commit -m "1"
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ chmod -r .hg/store/data/a.i
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
abort: Permission denied: $TESTTMP/t/.hg/store/data/a.i
[255]
$ chmod +r .hg/store/data/a.i
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ chmod -w .hg/store/data/a.i
$ echo barber > a
$ hg commit -m "2"
trouble committing a!
abort: Permission denied: $TESTTMP/t/.hg/store/data/a.i
[255]
$ chmod -w .
$ hg diff --nodates
diff -r 2a18120dc1c9 a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-foo
+barber
$ chmod +w .
$ chmod +w .hg/store/data/a.i
$ mkdir dir
$ touch dir/a
$ hg status
M a
? dir/a
$ chmod -rx dir
$ hg status
dir: Permission denied
M a
Reenable perm to allow deletion:
$ chmod +rx dir
$ cd ..