mdiff: don't emit a diff header for empty trivial deltas An empty trivial delta, coded as (0, 0, 0) makes the delta application do nothing, but still takes 12 bytes, while skipping it altogether works as much, without taking any space at all.

commands: get rid of empty try/finally block from _dograft This diff is purely an indentation change to clean up a block that was kept in place to make 77995317b374 easier to read.

commands: get rid of empty try/finally block from _dobackout This diff is purely an indentation change to clean up a block that was kept in place to make c7217f1458bf easier to read.

commands: get rid of empty try/finally block from import_ This diff is purely an indentation change to clean up a block that was kept in place to make 713b09fc9fbb easier to read.

streamclone: use context manager for writing files These are the file writes that have the most to gain from background I/O. Plug in a context manager so I can design the background I/O mechanism with context managers in mind.

scmutil: use context managers for file handles Now that we dropped support for Python 2.4, we are able to use context managers. Let's replace the try..finally pattern in scmutil.py with context managers, which close files automatically when the context manager is exited. There should be no change in behavior with this patch. Why convert to context managers if nothing is broken? I'm working on closing file handles in background threads to improve performance on Windows. As part of this, I realized there could be some future issues if the background file closing code isn't designed with context managers in mind. So, I'd like to switch some code to context managers so I can design an API that works with context managers.

statichttprepo: implement __enter__ and __exit__ on httprangeheader httprangeheader behaves like a file object. Implement __enter__ and __exit__ so it can be used as a context manager, just like file objects.

osutil: implement __enter__ and __exit__ on posixfile So they can be used as context managers.

util: introduce ctxmanager, to avoid nested try/finally blocks This is similar in spirit to contextlib.nested in Python <= 2.6, but uses an extra level of indirection to avoid its inability to clean up if an __enter__ method raises an exception. Why add this mechanism? It greatly simplifies scoped resource management, and lets us eliminate several hundred lines of try/finally blocks. In many of these cases the "finally" is separated from the "try" by hundreds of lines of code, which makes the connection between resource acquisition and disposal difficult to follow. (The preferred mechanism would be the "multi-with" syntax of 2.7+, but Mercurial can't move to 2.7 for a while.) Intended use: >>> with ctxmanager(lambda: file('foo'), lambda: file('bar')) as c: >>> f1, f2 = c() This will open both foo and bar when c() is invoked, and will close both upon exit from the block. If the attempt to open bar raises an exception, the block will not be entered - but foo will still be closed.

hghave: support HGMODULEPOLICY for pure HGMODULEPOLICY was introduced in 4374d819ccd5

merge with stable

tests: extend check-commit self-tests This now contains both positive and negative tests for almost all the check-commit rules.

encoding: handle UTF-16 internal limit with fromutf8b (issue5031) Default builds of Python have a Unicode type that isn't actually full Unicode but UTF-16, which encodes non-BMP codepoints to a pair of BMP codepoints with surrogate escaping. Since our UTF-8b hack escaping uses a plane that overlaps with the UTF-16 escaping system, this gets extra complicated. In addition, unichr() for codepoints greater than U+FFFF may not work either. This changes the code to reuse getutf8char to walk the byte string, so we only rely on Python for unpacking our U+DCxx characters.

bmstore: add handling of the active bookmark This further centralizes the handling of bookmark storage, and will help get some lingering bookmarks business out of localrepo. Right now, this change implies reading of the active bookmark to also imply reading all bookmarks from disk - for users with many many bookmarks this may be a measurable performance hit. In that case, we should migrate bmstore to be able to lazy-read its properties from disk rather than having to eagerly read them, but I decided to avoid doing that to try and avoid some potentially complicated filecache decorator issues. This doesn't move the logic for writing the active bookmark into a transaction, though that is probably the correct next step. Since the API probably needs to morph a little more, I didn't bother marking bookmarks.{activate,deactivate} as deprecated yet.

patchbomb: treat empty address list as no addresses Previously it wasn't possible to use configuration to avoid being prompted for e.g. a CC list when using patchbomb to send emails. We now make it possible to supply an empty value.

config: add hasconfig method and supporting plumbing We add the hasconfig method to make it possible to distinguish between a config value that was never supplied and one that is empty.