Commit a3242cc4 authored by Eli Zaretskii's avatar Eli Zaretskii

Improve documentation of Diff mode

* doc/emacs/files.texi (Diff Mode): Document the effect of
prefix argument on the Diff mode's commands.  Document
'diff-jump-to-old-file'.
parent 39e85a0c
......@@ -1427,23 +1427,30 @@ manually, type @kbd{M-x diff-mode}.
@cindex hunk, diff
The changes specified in a patch are grouped into @dfn{hunks}, which
are contiguous chunks of text that contain one or more changed lines.
Hunks can also include unchanged lines to provide context for the
Hunks usually also include unchanged lines to provide context for the
changes. Each hunk is preceded by a @dfn{hunk header}, which
specifies the old and new line numbers at which the hunk occurs. Diff
mode highlights each hunk header, to distinguish it from the actual
contents of the hunk.
specifies the old and new line numbers where the hunk's changes occur.
Diff mode highlights each hunk header, to distinguish it from the
actual contents of the hunk.
The first hunk in a patch is preceded by a file header, which shows
the names of the new and the old versions of the file, and their time
stamps. If a patch shows changes for more than one file, each file
has such a header before the first hunk of that file's changes.
@vindex diff-update-on-the-fly
You can edit a Diff mode buffer like any other buffer. (If it is
read-only, you need to make it writable first. @xref{Misc Buffer}.)
Whenever you change a hunk, Diff mode attempts to automatically
correct the line numbers in the hunk headers, to ensure that the patch
remains correct. To disable automatic line number correction,
change the variable @code{diff-update-on-the-fly} to @code{nil}.
Diff mode treats each hunk as an error message, similar to
Compilation mode. Thus, you can use commands such as @kbd{C-x `} to
visit the corresponding source locations. @xref{Compilation Mode}.
read-only, you need to make it writable first; see @ref{Misc Buffer}.)
Whenever you edit a hunk, Diff mode attempts to automatically correct
the line numbers in the hunk headers, to ensure that the patch remains
correct, and could still be applied by @command{patch}. To disable
automatic line number correction, change the variable
@code{diff-update-on-the-fly} to @code{nil}.
Diff mode arranges for hunks to be treated as compiler error
messages by @kbd{C-x `} and other commands that handle error messages
(@pxref{Compilation Mode}). Thus, you can use the compilation-mode
commands to visit the corresponding source locations.
In addition, Diff mode provides the following commands to navigate,
manipulate and apply parts of patches:
......@@ -1451,7 +1458,8 @@ manipulate and apply parts of patches:
@table @kbd
@item M-n
@findex diff-hunk-next
Move to the next hunk-start (@code{diff-hunk-next}).
Move to the next hunk-start (@code{diff-hunk-next}). With prefix
argument @var{n}, move forward to the @var{n}th next hunk.
@findex diff-auto-refine-mode
@cindex mode, Diff Auto-Refine
......@@ -1469,19 +1477,22 @@ default, add this to your init file (@pxref{Hooks}):
@item M-p
@findex diff-hunk-prev
Move to the previous hunk-start (@code{diff-hunk-prev}). Like
Move to the previous hunk-start (@code{diff-hunk-prev}). With prefix
argument @var{n}, move back to the @var{n}th previous hunk. Like
@kbd{M-n}, this has the side-effect of refining the hunk you move to,
unless you disable Diff Auto-Refine mode.
@item M-@}
@findex diff-file-next
Move to the next file-start, in a multi-file patch
(@code{diff-file-next}).
(@code{diff-file-next}). With prefix argument @var{n}, move forward
to the start of the @var{n}th next file.
@item M-@{
@findex diff-file-prev
Move to the previous file-start, in a multi-file patch
(@code{diff-file-prev}).
(@code{diff-file-prev}). With prefix argument @var{n}, move back to
the start of the @var{n}th previous file.
@item M-k
@findex diff-hunk-kill
......@@ -1496,7 +1507,10 @@ In a multi-file patch, kill the current file part.
@findex diff-apply-hunk
@cindex patches, applying
Apply this hunk to its target file (@code{diff-apply-hunk}). With a
prefix argument of @kbd{C-u}, revert this hunk.
prefix argument of @kbd{C-u}, revert this hunk, i.e.@: apply the
reverse of the hunk, which changes the ``new'' version into the ``old''
version. If @code{diff-jump-to-old-file} is non-@code{nil}, apply the
hunk to the ``old'' version of the file instead.
@item C-c C-b
@findex diff-refine-hunk
......@@ -1506,8 +1520,16 @@ of each changed line were actually changed.
@item C-c C-c
@findex diff-goto-source
@vindex diff-jump-to-old-file
Go to the source file and line corresponding to this hunk
(@code{diff-goto-source}).
(@code{diff-goto-source}). By default, this jumps to the ``new''
version of the file, the one shown first on the file header.
With a prefix argument, jump to the ``old'' version instead. If
@code{diff-jump-to-old-file} is non-@code{nil}, this command by
default jumps to the ``old'' file, and the meaning of the prefix
argument is reversed. If the prefix argument is a number greater than
8 (e.g., if you type @kbd{C-u C-u C-c C-c}), then this command also
sets @code{diff-jump-to-old-file} for the next invocation.
@item C-c C-e
@findex diff-ediff-patch
......@@ -1517,41 +1539,47 @@ Start an Ediff session with the patch (@code{diff-ediff-patch}).
@item C-c C-n
@findex diff-restrict-view
Restrict the view to the current hunk (@code{diff-restrict-view}).
@xref{Narrowing}. With a prefix argument of @kbd{C-u}, restrict the
@xref{Narrowing}. With a prefix argument, restrict the
view to the current file of a multiple-file patch. To widen again,
use @kbd{C-x n w} (@code{widen}).
@item C-c C-r
@findex diff-reverse-direction
Reverse the direction of comparison for the entire buffer
(@code{diff-reverse-direction}).
(@code{diff-reverse-direction}). With a prefix argument, reverse the
direction only inside the current region (@pxref{Mark}). Reversing
the direction means changing the hunks and the file-start headers to
produce a patch that would change the ``new'' version into the ``old''
one.
@item C-c C-s
@findex diff-split-hunk
Split the hunk at point (@code{diff-split-hunk}). This is for
manually editing patches, and only works with the @dfn{unified diff
format} produced by the @option{-u} or @option{--unified} options to
the @command{diff} program. If you need to split a hunk in the
@dfn{context diff format} produced by the @option{-c} or
@option{--context} options to @command{diff}, first convert the buffer
to the unified diff format with @kbd{C-c C-u}.
Split the hunk at point (@code{diff-split-hunk}) into two separate
hunks. This inserts a hunk header and modifies the header of the
current hunk. This command is useful for manually editing patches,
and only works with the @dfn{unified diff format} produced by the
@option{-u} or @option{--unified} options to the @command{diff}
program. If you need to split a hunk in the @dfn{context diff format}
produced by the @option{-c} or @option{--context} options to
@command{diff}, first convert the buffer to the unified diff format
with @kbd{C-c C-u}.
@item C-c C-d
@findex diff-unified->context
Convert the entire buffer to the @dfn{context diff format}
(@code{diff-unified->context}). With a prefix argument, convert only
the text within the region.
the hunks within the region.
@item C-c C-u
@findex diff-context->unified
Convert the entire buffer to unified diff format
(@code{diff-context->unified}). With a prefix argument, convert
unified format to context format. When the mark is active, convert
only the text within the region.
only the hunks within the region.
@item C-c C-w
@findex diff-ignore-whitespace-hunk
Re-diff the current hunk, disregarding changes in whitespace
Re-generate the current hunk, disregarding changes in whitespace
(@code{diff-ignore-whitespace-hunk}).
@item C-x 4 A
......@@ -1582,7 +1610,8 @@ that whitespace in both the patch and the patched source file(s).
This command does not save the modifications that it makes, so you can
decide whether to save the changes (the list of modified files is
displayed in the echo area). With a prefix argument, it tries to
modify the original source files rather than the patched source files.
modify the original (``old'') source files rather than the patched
(``new'') source files.
@node Copying and Naming
@section Copying, Naming and Renaming Files
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment