Re: 23.0.60; Deja vu font breaks mouse-face highlighting in Gnus

[Stephen Berman <Stephen.Berman@gmx.net>]

On Mon, 11 Feb 2008 16:47:28 +0100 Stephen Berman <Stephen.Berman@gmx.net> wrote:

> 1. emacs -Q
> 2. Eval this:
>    (setq gnus-summary-line-format "%U%R%z%((%4L) %-20,20f \x2502 %*%B%s%)\n"
> 	  gnus-sum-thread-tree-root "\x25b6 "
> 	  gnus-sum-thread-tree-false-root "\x25b7 "
> 	  gnus-sum-thread-tree-vertical "\x2502 "
> 	  gnus-sum-thread-tree-leaf-with-other "\x251c\x2500\x25b8 ..."
> 	  gnus-sum-thread-tree-single-leaf "\x2570\x2500\x25b8 ...")
> 3. M-x gnus, browse a group that has threaded messages and see the fancy
> threading display produced by the above settings in the Summary buffer.
> 4. Select a subject header in the Summary buffer, such that the subject
> contains one of the fancy threading characters, or one of the strings
> "Re: ", "RE: ", "23.", "2.", and place the cursor on one of these
> characters (on the first character in the strings "Re: ", "RE: ", "23.",
> "2.").
> 5. Move the mouse over the subject header and observe the highlighting
> everywhere except the character after the cursor (in the case of
> "\x251c\x2500\x25b8 ..." and "\x2570\x2500\x25b8 ...", if the cursor is
> over "\x2500", the both the immediately preceding and immediately
> following characters are not highlighted).
>
> Repeat the above in Emacs 23.0.50 but with the following settings in
> step 2 (since the above are invalid characters in pre-unicode-2 Emacs):
>    (setq gnus-summary-line-format "%U%R%z%((%4L) %-20,20f \x49022 %*%B%s%)\n"
> 	    gnus-sum-thread-tree-root "\x490f6 "
> 	    gnus-sum-thread-tree-false-root "\x490f7 "
> 	    gnus-sum-thread-tree-leaf-with-other "\x4903c\x49020\x490fa ..."
> 	    gnus-sum-thread-tree-vertical "\x49022"
> 	    gnus-sum-thread-tree-single-leaf "\x490b0\x49020\x490fa ...")
> Now at step 5 the entire subject shows mouse-face highlighting as it
> should, i.e. no gaps.

I made a mistake above: either step 1 should be this:

1'. emacs -Q -fn "Dejavu Sans Mono"

or before step 5 use set-frame-font to switch to Dejavu Sans Mono (then
it's without anti-aliasing, but that does not matter).  Other Dejavu
fonts also show the gap in highlighting, but the range of susceptible
strings seems to be less than with Dejavu Sans Mono.  I have tried using
a number of other fonts but so far haven't found any others that show
the display problem.

Steve Berman