mercurial/help/diffs.txt
author Bryan O'Sullivan <bryano@fb.com>
Thu, 21 Mar 2013 22:10:54 -0700
changeset 18796 fa6d5c62f3bd
parent 12083 ebfc46929f3e
permissions -rw-r--r--
pathcomplete: complete directories more conservatively Suppose we want to perform a single-level completion (i.e. without --full) of "fi" in a repo containing "fee", "fie/dead", "fie/live", and "foe". If we give back "fie/" as the only answer, the shell will consider the completion to be unambiguous, and will append a space after the completion. We can't complete "fie/live" or "fie/dead" without first backspacing over that space. We used to thus create two fake names, "fie/a" and "fie/b", to force the shell to consider the completion to be ambiguous. It would then stop at "fie/" without appending a space, allowing us to hit tab again to complete "fie/live" or "fie/dead". The change here arises from realising that we only need to force the shell to consider a completion as ambiguous if we have exactly one directory and zero files as possible completions. This prevents spurious names from showing up as possible completions when they don't need to be invented in the first place.

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.