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.
