view mercurial/helptext/diffs.txt @ 44372:8407031f195f

bookmarks: prevent pushes of divergent bookmarks (foo@remote)

Before this change, such bookmarks are write-only: a client can push
them but not pull/read them. And because these bookmark can't be read,
even pushes are limited (for instance trying to delete such a bookmark
fails with a vanilla client because the client thinks the bookmark is
neither on the local nor the remote).

This change makes the server refuses such bookmarks, and for earlier
errors, makes the client refuse to send them.

I think the change of behavior is acceptable because I think this is a
bug in push/pull, and I don't think we change the behavior of `hg
unbundle`, because it doesn't seem that `hg bundle` ever store
bookmarks (and even if it did, it would seem weird anyway to try to
send divergent bookmarks).

Differential Revision: https://phab.mercurial-scm.org/D8117

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.