view mercurial/help/diffs.txt @ 37290:cc5a040fe150

wireproto: syntax for encoding CBOR into frames We just vendored a library for encoding and decoding the CBOR data format. While the intent of that vendor was to support state files, CBOR is really a nice data format. It is extensible and compact. I've been feeling dirty inventing my own data formats for frame payloads. While custom formats can always beat out a generic format, there is a cost to be paid in terms of implementation, comprehension, etc. CBOR is compact enough that I'm not too worried about efficiency loss. I think the benefits of using a standardized format outweigh rolling our own formats. So I plan to make heavy use of CBOR in the wire protocol going forward. This commit introduces support for encoding CBOR data in frame payloads to our function to make a frame from a human string. We do need to employ some low-level Python code in order to evaluate a string as a Python expression. But other than that, this should hopefully be pretty straightforward. Unit tests for this function have been added. Differential Revision: https://phab.mercurial-scm.org/D2948
author Gregory Szorc <gregory.szorc@gmail.com>
date Wed, 28 Mar 2018 15:05:39 -0700
parents ebfc46929f3e
children
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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.