view mercurial/helptext/diffs.txt @ 46487:839cacdff919 stable

tweak-default: no longer enable the experimental return code

The change is quite new and undocumented (since it is experimental) so it seems
premature to make it available in tweak default. In addition, I am not sure the
new return code are frozen yet (eg: some of the initial feedback have not been
incorporated). Before the release I doubled check (probably with Martin) that
they were not enabled by default and got replied that they were only enabled in
the tests. Have I been aware that they have been also enabled in tweak default I
would I have lobbied to delay that.

I discovered they were in tweak default from users feedback. They found it an
unpleasant and unexpected surprise of 5.7.

So I suggest we no enable enable this experimental feature for Mercurial 5.7 and
revisit this later, when the feature will be more mature.

Differential Revision: https://phab.mercurial-scm.org/D9975

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.