hooks: add HG_NODE_LAST to txnclose and changegroup hook environments
Sometimes a txnclose or changegroup hook wants to iterate through all
the changesets in transaction: in that situation usually the revset
`$HG_NODE:` is used to select the revisions. Unfortunately this revset
sometimes may contain too many changesets because we don't have the
write lock while the hook runs newer changes may be added to
repository in the meantime.
That's why there is a need for extra variable carrying the information about
the last change in the transaction.
$ hg init
$ echo a > a
$ hg ci -Am0
adding a
$ hg -q clone . foo
$ touch .hg/store/journal
$ echo foo > a
$ hg ci -Am0
abort: abandoned transaction found!
(run 'hg recover' to clean up transaction)
[255]
$ hg recover
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
Check that zero-size journals are correctly aborted:
#if unix-permissions no-root
$ hg bundle -qa repo.hg
$ chmod -w foo/.hg/store/00changelog.i
$ hg -R foo unbundle repo.hg
adding changesets
abort: Permission denied: $TESTTMP/foo/.hg/store/.00changelog.i-* (glob)
[255]
$ if test -f foo/.hg/store/journal; then echo 'journal exists :-('; fi
#endif