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 diff
+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}.
functions that are deleted by the patch.
@end table
- By default, Diff mode highlights trailing whitespace on modified
-lines, so that they are more obvious. This is done by enabling
-Whitespace mode in the Diff buffer (@pxref{Useless Whitespace}). Diff
-mode buffers are set up so that Whitespace mode avoids highlighting
-trailing whitespace occurring in the diff context.
+@c Trailing whitespace is NOT shown by default.
+@c Emacs's dir-locals file enables this (for some reason).
+@cindex trailing whitespace, in patches
+@findex diff-delete-trailing-whitespace
+ Patches sometimes include trailing whitespace on modified lines, as
+an unintentional and undesired change. There are two ways to deal
+with this problem. Firstly, if you enable Whitespace mode in a Diff
+buffer (@pxref{Useless Whitespace}), it automatically highlights
+trailing whitespace in modified lines. Secondly, you can use the
+command @kbd{M-x diff-delete-trailing-whitespace}, which searches for
+trailing whitespace in the lines modified by the patch, and removes
+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.
@node Misc File Ops
@section Miscellaneous File Operations
@var{target} at the time the opening is done, or will get an error if
the name @var{target} is nonexistent at that time. This command does
not expand the argument @var{target}, so that it allows you to specify
-a relative name as the target of the link. Not all systems support
-symbolic links; on systems that don't support them, this command is
-not defined.
+a relative name as the target of the link. On MS-Windows, this
+command works only on MS Windows Vista and later.
@kindex C-x i
@findex insert-file
files.
@cindex ImageMagick support
- If your Emacs was compiled with ImageMagick support, it is possible
-to view a much wider variety of image types in Image mode, by
-rendering the images via ImageMagick. However, this feature is
-currently disabled by default. To enable it, add the following line
-to your init file:
-
-@example
-(imagemagick-register-types)
-@end example
+@vindex imagemagick-enabled-types
+@vindex imagemagick-types-inhibit
+ If Emacs was compiled with support for the ImageMagick library, it
+can use ImageMagick to render a wide variety of images. The variable
+@code{imagemagick-enabled-types} lists the image types that Emacs may
+render using ImageMagick; each element in the list should be an
+internal ImageMagick name for an image type, as a symbol or an
+equivalent string (e.g.@: @code{BMP} for @file{.bmp} images). To
+enable ImageMagick for all possible image types, change
+@code{imagemagick-enabled-types} to @code{t}. The variable
+@code{imagemagick-types-inhibit} lists the image types which should
+never be rendered using ImageMagick, regardless of the value of
+@code{imagemagick-enabled-types} (the default list includes types like
+@code{C} and @code{HTML}, which ImageMagick can render as an ``image''
+but Emacs should not). To disable ImageMagick entirely, change
+@code{imagemagick-types-inhibit} to @code{t}.
@findex thumbs-mode
@findex mode, thumbs