streamclone: indent code This will make the subsequent patch easier to read.

scmutil: support background file closing Closing files that have been appended to is relatively slow on Windows/NTFS. This makes several Mercurial operations slower on Windows. The workaround to this issue is conceptually simple: use multiple threads for I/O. Unfortunately, Python doesn't scale well to multiple threads because of the GIL. And, refactoring our code to use threads everywhere would be a huge undertaking. So, we decide to tackle this problem by starting small: establishing a thread pool for closing files. This patch establishes a mechanism for closing file handles on separate threads. The coordinator object is basically a queue of file handles to operate on and a thread pool consuming from the queue. When files are opened through the VFS layer, the caller can specify that delay closing is allowed. A proxy class for file handles has been added. We must use a proxy because it isn't possible to modify __class__ on built-in types. This adds some overhead. But as future patches will show, this overhead is cancelled out by the benefit of closing file handles on background threads.

templatekw: add {namespaces} keyword This provides a general-purpose interface to all custom namespaces. The {namespaces} keyword honors the definition order of namespaces as they are kept by sortdict.

templatekw: move shownames() helper to be sorted alphabetically I'll add shownamespaces(), which is similar to this function. I want to put them nearby.

templater: make get(dict, key) return a single value This is necessary to obtain a _hybrid object from a dict. If get() yields a value, it would be stringified. I see no benefit to make get() lazy, so this patch just changes "yield" to "return".

templater: make _hybrid not callable to avoid conflicting semantics In templater, a callable symbol exists for lazy evaluation, which should have f(**mapping) signature. On the other hand, _hybrid.__call__(), which was introduced by 0b241d7a8c62, generates mapping for each element. This patch renames _hybrid.__call__() to _hybrid.itermaps() so that a _hybrid object can be a value of a mapping dict. {namespaces % "{namespace}: {names % "{name }"}\n"} ~~~~~ a _hybrid object

backout: commit changeset by default (BC) Add --no-commit flag to prevent it. This should make the hg user experience a little better. Some discussion can be found here: http://markmail.org/message/7jm7ro2ias6hxywy

help: move Windows 9x information to appropriate place

shelve: move commitfunc closer to use site Supporting shelving of unknown files needs this code motion. No functional changes.

commands: document clone bundles hooks and rollback behavior The added content is inside a verbose container. I figure it makes sense to explicitly document behavior, including with the caveat it may change later. People can't say they weren't warned!