Re: fringe arrow conflict between compile and gud?

[Juri Linkov]

> It looks good now. In compilation-sentinel you might like to add:
>
>    ;; buffer killed
>    (set-process-buffer proc nil)
> +  (delq 'next-error-overlay-arrow-position overlay-arrow-variable-list)
>
> although I don't know what the performance penalty is, if any, if you don't.

This is not the right place to put this code.  The better place is
`kill-buffer-hook'.  And removing next-error-overlay-arrow-position
from overlay-arrow-variable-list is not good after killing the
compilation buffer because there be be other existing compilation/grep
buffers, where users might want to navigate to their locations with
`next-error'.  But anyway thanks for the hint about the case
of killing the compilation buffer.  I think next-error-overlay-arrow-position
should be set to nil in the local hook kill-buffer-hook.
This might remove the arrow associated with another compilation/grep
buffer since they all share the same next-error arrow, but this is
better than to leave the next-error arrow after killing the compilation
buffer.

The lines
(set (make-local-variable 'overlay-arrow-string) "=>")
and
(put 'next-error-overlay-arrow-position 'overlay-arrow-string "=>")
exist in the following patch until Kim decides to set
overlay-arrow-string to "=>" by default.

Index: lisp/progmodes/compile.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/progmodes/compile.el,v
retrieving revision 1.348
diff -u -r1.348 compile.el
--- lisp/progmodes/compile.el   29 Mar 2005 04:56:44 -0000      1.348
+++ lisp/progmodes/compile.el   2 Apr 2005 00:16:31 -0000
@@ -1233,6 +1233,11 @@
   (make-local-variable 'compilation-messages-start)
   (make-local-variable 'compilation-error-screen-columns)
   (make-local-variable 'overlay-arrow-position)
+  (set (make-local-variable 'overlay-arrow-string) "=>")
+  (setq next-error-overlay-arrow-position nil)
+  (add-to-list 'overlay-arrow-variable-list 'next-error-overlay-arrow-position)
+  (add-hook 'kill-buffer-hook
+           (lambda () (setq next-error-overlay-arrow-position nil)) nil t)
   ;; Note that compilation-next-error-function is for interfacing
   ;; with the next-error function in simple.el, and it's only
   ;; coincidentally named similarly to compilation-next-error.
@@ -1641,8 +1646,9 @@
                         (numberp next-error-highlight)))
                (delete-overlay compilation-highlight-overlay))))))
     (when (and (eq next-error-highlight 'fringe-arrow))
-      (set (make-local-variable 'overlay-arrow-position)
-          (copy-marker (line-beginning-position))))))
+      (setq next-error-overlay-arrow-position
+           (copy-marker (line-beginning-position))))))
+
 
 (defun compilation-find-file (marker filename dir &rest formats)
   "Find a buffer for file FILENAME.

Index: lisp/simple.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/simple.el,v
retrieving revision 1.705
diff -u -r1.705 simple.el
--- lisp/simple.el      29 Mar 2005 23:17:30 -0000      1.705
+++ lisp/simple.el      2 Apr 2005 00:15:56 -0000
@@ -114,6 +114,9 @@
 
 (defvar next-error-highlight-timer nil)
 
+(defvar next-error-overlay-arrow-position nil)
+(put 'next-error-overlay-arrow-position 'overlay-arrow-string "=>")
+
 (defvar next-error-last-buffer nil
   "The most recent next-error buffer.
 A buffer becomes most recent when its compilation, grep, or

-- 
Juri Linkov
http://www.jurta.org/emacs/