localrepo: pass hook argument txnid to pretxnopen hooks Before this patch, hook argument `txnid` isn't passed to `pretxnopen` hooks, even though `hooks` section of `hg help config` describes so. ``pretxnopen`` Run before any new repository transaction is open. The reason for the transaction will be in ``$HG_TXNNAME`` and a unique identifier for the transaction will be in ``HG_TXNID``. A non-zero status will prevent the transaction from being opened.

transaction: separate calculating TXNID from creating transaction object Before this patch, transaction ID (TXNID) is calculated from `transaction` object itself by `id()`, but this prevents TXNID from being passed to `pretxnopen` hooks, which should be executed before starting transaction processing (also any preparations for it, like writing journal files out). As a preparation for passing TXNID to `pretxnopen` hooks, this patch separates calculation of TXNID from creation of `transaction` object. This patch uses "random" library for reasonable unique ID. "uuid" library can't be used, because it was introduced since Python 2.5 and isn't suitable for Mercurial 3.4.x stable line. `%f` formatting for `random.random()` is used with explicit precision number 40, because default precision for `%f` is 6. 40 should be long enough, even if 10**9 transactions are executed in a short time (a second or less). On the other hand, `time.time()` is used to ensures uniqueness of TXNID in a long time, for safety. BTW, platform not providing `/dev/urandom` or so may cause failure of `import random` itself with some Python versions (see Python issue15340 for detail http://bugs.python.org/issue15340). But this patch uses "random" without any workaround, because: - "random" is already used directly in some code paths, - such platforms are very rare (e.g. Tru64 and HPUX), and http://bugs.python.org/issue15340#msg170000 - updating Python runtime can avoid this issue

revbranchcache: return uncached branchinfo for nullrev (issue4683) This fixes the crash caused by "branch(null)" revset. No cache should be necessary for nullrev because changelog.branchinfo(nullrev) does not involve IO operation. Note that the problem of "branch(wdir())" isn't addressed by this patch. "wdir()" will raise TypeError in many places because of None. This is the reason why "wdir()" is still experimental.

revset: drop magic of fullreposet membership test (issue4682) This patch partially backs out d2de20e1451f and adds an alternative workaround to functions that evaluate "null" and "wdir()". Because the new workaround is incomplete, "first(null)" and "min(null)" don't work as expected. But they were not usable until 3.4 and "null" isn't commonly used, we can postpone a complete fix for 3.5. The issue4682 was caused because "branch(default)" is evaluated to "<filteredset <fullreposet>>", keeping fullreposet magic. The next patch will fix crash on "branch(null)", but without this patch, it would make "null in <branch(default)>" be True, which means "children(branch(default))" would return all revisions but merge (p2 != null). I believe the right fix is to stop propagating fullreposet magic on filter(), but it wouldn't fit to stable release. Also, we should discuss how to handle "null" and "wdir()" in revset before.

merge with stable

transaction: use the proper variable in '_addbackupentry' (issue4684) The 'file' variable was undefined but resolved to the 'file' built-in. This is why pylint complains about overwriting built-ins...

run-tests: python3.5 now supports mkdtemp using bytes for paths Now that http://bugs.python.org/issue24230 is fixed (thanks to Gregory Smith for that quick response!) we can drop one more ugly hack around path handling. Tests still pass in 3.5 with this cleaner version, as well as in 2.6.

run-tests: use items() instead of iteritems() This fixes the python3.5 build. We'll presumably want to build our own helper function or use 2to3 for this on the main source tree, but for run-tests we want a single-source version that works in 2.6 and 3.5.

selve: make 'shelve --interactive' not experimental It is safe to do as 'shelve -i' uses the same code path as 'commit -i' that is not experimental.

revert: fix edition of newly added file during --interactive Before this patch: editing hunks of newly added file when performing a revert --interactive had no effect: the edits were discarded. After this patch, the edits are taken into account.

revert: make revert --interactive use git style diff This allows us to use existing code to detect files that are newly added and modified. In turn, this allows us to make revert --interactive support editing newly added and modified files.

record: extract code to compute newly added and modified files We want to reuse this logic in revert.

record: extract ishunk to a function We extract this code as we want to reuse it in revert -i.

fileset: pretty print syntax tree in debug output

parser: extract closure of prettyformat() to a top-level function There was no capture until I added 'leafnodes' argument.

parser: move prettyformat() function from revset module I want to use it in doctests that I'll add by future patches. Also, it can be used in "hg debugfileset" command.