bug#14134: 24.3; Delphi Mode Doesn't Work With Highlight Changes Mode

bug#14134: 24.3; Delphi Mode Doesn't Work With Highlight Changes Mode

[Erik Knowles]

Delphi mode's fontification code erases all existing text properties, including those used by highlight
changes mode to mark modified text sections. 

To duplicate:

emacs -Q
<emacs responds with the scratch buffer>
M-x delphi-mode
M-x highlight-changes-mode
<type some text -- the text will be shown with the highlight-changes face>
M-x highlight-changes-visible-mode
<text is shown in the default face>
M-x highlight-changes-visible-mode
<At this point the text will still be shown in the default face instead of the
highlight-changes face>

I've not included a proper patch (intuitively, the "correct" fix would be to rewrite Delphi mode's
fontification code to use overlays) because I'm not experienced enough with Elisp to do a
proper job; however, I've personally worked around the problem by monkey patching 
as follows:

-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~

;; Delphi-mode marks literals with special text properties, in the process borking *all*
;; existing properties including the properties used by hilit-chg mode for marking
;; changes even when the "changes visible" flag is off. To avoid this, the mode's
;; "delphi-set-text-properties" function is replaced here with a version that simply
;; removes the specific text properties used by the font lock while leaving all the
;; other properties alone.
;;
;; To do this delphi-set-text-properties simply tracks which faces are used by the Delphi
;; font lock code and only removes those faces
(setq delphi-used-faces (list))
(defun delphi-set-text-properties (from to properties)
  ;; Like `set-text-properties', except we do not consider this to be a buffer
  ;; modification.
  (delphi-save-state 
    (dolist (prop delphi-used-faces) (remove-text-properties from to prop))
    (when properties
      (add-text-properties from to properties)
      (add-to-list 'delphi-used-faces properties) 
    )
  ) 
)                   

-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~


In GNU Emacs 24.3.1 (i686-pc-cygwin)
 of 2013-03-11 on fiona
Configured using:
 `configure '--srcdir=/home/kbrown/src/cygemacs/emacs-24.3-1/src/emacs-24.3'
 '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin'
 '--libexecdir=/usr/lib' '--datadir=/usr/share' '--localstatedir=/var' '--sysconfdir=/etc'
 '--datarootdir=/usr/share' '--docdir=/usr/share/doc/emacs' '-C' '--with-x=no' 'CC=gcc'
 'CFLAGS=-ggdb -O2 -pipe
 -fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.3-1/build=/usr/src/debug/emacs-24.3-1
 -fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.3-1/src/emacs-24.3=/usr/src/debug/emacs-24.3-1'
 'LDFLAGS=-L/usr/lib/ncursesw' 'LIBS=' 'CPPFLAGS=-I/usr/include/ncursesw''

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  flyspell-mode: t
  shell-dirtrack-mode: t
  mouse-wheel-mode: t
  xterm-mouse-mode: t
  global-subword-mode: t
  subword-mode: t
  cua-mode: t
  desktop-save-mode: t
  show-paren-mode: t
  global-highlight-changes-mode: t
  highlight-changes-mode: t
  which-function-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  auto-fill-function: do-auto-fill
  transient-mark-mode: t


Load-path shadows:
/home/Erik/.emacs.d/indent hides /usr/share/emacs/24.3/lisp/indent

Features:
(shadow gnus-util mail-extr emacsbug message format-spec rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils server flyspell ispell ido tempbuf
grep-a-lot grep bash-completion shell pcomplete init-terminal-fix saveplace tabbar mwheel
xt-mouse backup-dir backup-each-save pascal-mode+ delphi pascal subword org-install
xterm-title xterm-frobs goto-last-change cua-base sunrise-commander easy-mmode term ehelp
electric sort find-dired esh-var esh-io esh-cmd esh-opt esh-ext esh-proc esh-arg eldoc
esh-groups eshell esh-util esh-module esh-mode disp-table enriched dired-x easymenu
dired-aux dired desktop paren hl-line+ advice help-fns cl-lib advice-preload time-date
hl-line hilit-chg wid-edit which-func imenu edmacro kmacro warnings byte-opt compile
comint regexp-opt ansi-color ring tool-bar bytecomp byte-compile cconv
bash-completion-autoloads cygwin-mount-autoloads dired+-autoloads flymake-cursor-autoloads
flymake-python-pyflakes-autoloads flymake-easy-autoloads grep-a-lot-autoloads
hl-line+-autoloads icicles-autoloads pager-autoloads tabbar-autoloads tidy-autoloads
package ediff-hook vc-hooks lisp-float-type tabulated-list newcomment lisp-mode register
page menu-bar rfn-eshadow timer select mouse jit-lock font-lock syntax facemenu font-core
frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process dbusbind multi-tty
emacs)


- Erik R. Knowles

bug#14134: 24.3; Delphi Mode Doesn't Work With Highlight Changes Mode

[Stefan Monnier]

> Delphi mode's fontification code erases all existing text properties,
> including those used by highlight changes mode to mark modified
> text sections. 

I think your "monkey" patch was actually a fairly good idea.
I installed the patch below instead, which seems a bit cleaner.
I don't think this is quite good enough, but it's a step in the
right direction.


        Stefan


=== modified file 'lisp/ChangeLog'
--- lisp/ChangeLog	2013-04-24 14:35:59 +0000
+++ lisp/ChangeLog	2013-04-24 20:40:19 +0000
@@ -1,3 +1,11 @@
+2013-04-24  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* progmodes/opascal.el (opascal-set-token-property): Rename from
+	opascal-set-text-properties and only set `token' (bug#14134).
+	(opascal-literal-text-properties): Remove.
+	(opascal-parse-next-literal, opascal-debug-unparse-buffer):
+	Adjust callers.
+
 2013-04-24  Reuben Thomas <rrt@sc3d.org>
 
 	* textmodes/remember.el (remember-handler-functions): Add an

=== modified file 'lisp/progmodes/opascal.el'
--- lisp/progmodes/opascal.el	2013-01-31 01:58:24 +0000
+++ lisp/progmodes/opascal.el	2013-04-24 20:38:48 +0000
@@ -406,11 +406,11 @@
 non-OPascal buffer.  Set to nil in OPascal buffers.  To override, just do:
  (let ((opascal--ignore-changes t)) ...)")
 
-(defun opascal-set-text-properties (from to properties)
+(defun opascal-set-token-property (from to value)
   ;; Like `set-text-properties', except we do not consider this to be a buffer
   ;; modification.
   (opascal-save-state
-   (set-text-properties from to properties)))
+   (put-text-property from to 'token value)))
 
 (defun opascal-literal-kind (p)
   ;; Returns the literal kind the point p is in (or nil if not in a literal).
@@ -490,13 +490,6 @@
       (re-search-forward pattern limit 'goto-limit-on-fail)
       (point))))
 
-(defun opascal-literal-text-properties (kind)
-  ;; Creates a list of text properties for the literal kind.
-  (if (and (boundp 'font-lock-mode)
-           font-lock-mode)
-      (list 'token kind 'face (opascal-face-of kind) 'lazy-lock t)
-    (list 'token kind)))
-
 (defun opascal-parse-next-literal (limit)
   ;; Searches for the next literal region (i.e. comment or string) and sets the
   ;; the point to its end (or the limit, if not found). The literal region is
@@ -507,8 +500,7 @@
            ;; We are completing an incomplete literal.
            (let ((kind (opascal-literal-kind (1- search-start))))
              (opascal-complete-literal kind limit)
-             (opascal-set-text-properties
-              search-start (point) (opascal-literal-text-properties kind))))
+             (opascal-set-token-property search-start (point) kind)))
 
           ((re-search-forward
             "\\(//\\)\\|\\({\\)\\|\\((\\*\\)\\|\\('\\)\\|\\(\"\\)"
@@ -520,13 +512,12 @@
                              ((match-beginning 4) 'string)
                              ((match-beginning 5) 'double-quoted-string)))
                  (start (match-beginning 0)))
-             (opascal-set-text-properties search-start start nil)
+             (opascal-set-token-property search-start start nil)
              (opascal-complete-literal kind limit)
-             (opascal-set-text-properties
-              start (point) (opascal-literal-text-properties kind))))
+             (opascal-set-token-property start (point) kind)))
 
           ;; Nothing found. Mark it as a non-literal.
-          ((opascal-set-text-properties search-start limit nil)))
+          ((opascal-set-token-property search-start limit nil)))
     (opascal-step-progress (point) "Parsing" opascal-parsing-progress-step)))
 
 (defun opascal-literal-token-at (p)
@@ -1570,7 +1561,7 @@
 
 (defun opascal-debug-unparse-buffer ()
   (interactive)
-  (opascal-set-text-properties (point-min) (point-max) nil))
+  (opascal-set-token-property (point-min) (point-max) nil))
 
 (defun opascal-debug-parse-region (from to)
   (interactive "r")

bug#14134: 24.3; Delphi Mode Doesn't Work With Highlight Changes Mode

[Stefan Monnier]

This should be all fixed now: I changed opascal-mode to use
syntax-propertize and font-lock "in the normal way".


        Stefan