Mercurial's default format for showing changes between two versions of

a file is compatible with the unified format of GNU diff, which can be

used by GNU patch and many other standard tools.

While this standard format is often enough, it does not encode the

following information:

- executable status and other permission bits

- copy or rename information

- changes in binary files

- creation or deletion of empty files

Mercurial also supports the extended diff format from the git VCS

which addresses these limitations. The git diff format is not produced

by default because a few widespread tools still do not understand this

format.

This means that when generating diffs from a Mercurial repository

(e.g. with :hg:`export`), you should be careful about things like file

copies and renames or other things mentioned above, because when

applying a standard diff to a different repository, this extra

information is lost. Mercurial's internal operations (like push and

pull) are not affected by this, because they use an internal binary

format for communicating changes.

To make Mercurial produce the git extended diff format, use the --git

option available for many commands, or set 'git = True' in the [diff]

section of your configuration file. You do not need to set this option

when importing diffs in this format or using them in the mq extension.