Package: emacs;
Reported by: Felician Nemeth <felician.nemeth <at> gmail.com>
Date: Sun, 19 Jan 2020 11:15:02 UTC
Severity: normal
Found in version 28.0.50
View this message in rfc822 format
From: Stefan Monnier <monnier <at> iro.umontreal.ca> To: Juri Linkov <juri <at> linkov.net> Cc: 39190 <at> debbugs.gnu.org, Felician Nemeth <felician.nemeth <at> gmail.com> Subject: bug#39190: 28.0.50; two buffers with same buffer-file-name (diff-syntax-fontify-props) Date: Tue, 18 Feb 2020 18:31:38 -0500
>> Maybe a simpler variant would be to use some other variable to distinguish
>> sub-mode and its parent, instead of relying on delay-mode-hooks?
>
> That's kinda hard if you want to use define-derived-mode and we do: when
> we call `conf-foo-mode` the first things it does is: bind
> `delay-mode-hooks` and call the parent (`conf-mode`), so the only
> difference between this call to the parent and a direct call to the
> generic entry point is the binding of `delay-mode-hooks`.
IOW, I think we should start with something like the patch below which
makes `conf-guess-mode` available, after which we can start fixing the
various callers to call `conf-guess-mode` instead.
Stefan
diff --git a/lisp/textmodes/conf-mode.el b/lisp/textmodes/conf-mode.el
index 86db698043..b3325eeff6 100644
--- a/lisp/textmodes/conf-mode.el
+++ b/lisp/textmodes/conf-mode.el
@@ -351,7 +351,37 @@ conf-outline-level
;;;###autoload
-(defun conf-mode ()
+(defun conf-guess-mode ()
+ "Enable the conf-*-mode that seems most appropriate."
+ (let ((unix 0) (win 0) (equal 0) (colon 0) (space 0) (jp 0))
+ (save-excursion
+ (goto-char (point-min))
+ (while (not (eobp))
+ (skip-chars-forward " \t\f")
+ (cond ((eq (char-after) ?\#) (setq unix (1+ unix)))
+ ((eq (char-after) ?\;) (setq win (1+ win)))
+ ((eq (char-after) ?\[)) ; nop
+ ((eolp)) ; nop
+ ((eq (char-after) ?})) ; nop
+ ;; recognize at most double spaces within names
+ ((looking-at "[^ \t\n=:]+\\(?: ?[^ \t\n=:]+\\)*[ \t]*[=:]")
+ (if (eq (char-before (match-end 0)) ?=)
+ (setq equal (1+ equal))
+ (setq colon (1+ colon))))
+ ((looking-at "/[/*]") (setq jp (1+ jp)))
+ ((looking-at ".*{")) ; nop
+ ((setq space (1+ space))))
+ (forward-line)))
+ (cond
+ ((> jp (max unix win 3)) (conf-javaprop-mode))
+ ((> colon (max equal space)) (conf-colon-mode))
+ ((> space (max equal colon)) (conf-space-mode))
+ ((or (> win unix) (and (= win unix) (eq system-type 'windows-nt)))
+ (conf-windows-mode))
+ (t (conf-unix-mode)))))
+
+;;;###autoload
+(define-derived-mode conf-mode nil "Conf[?]"
"Mode for Unix and Windows Conf files and Java properties.
Most conf files know only three kinds of constructs: parameter
assignments optionally grouped into sections and comments. Yet
@@ -372,7 +402,7 @@ conf-mode
quite right. Patches that clearly identify some special case,
without breaking the general ones, are welcome.
-If instead you start this mode with the generic `conf-mode'
+If instead you start this mode with the generic `conf-guess-mode'
command, it will parse the buffer. It will generally well
identify the first four cases listed below. If the buffer
doesn't have enough contents to decide, this is identical to
@@ -381,46 +411,13 @@ conf-mode
`conf-ppd-mode' and `conf-xdefaults-mode'.
\\{conf-mode-map}"
-
- (interactive)
- ;; `conf-mode' plays two roles: it's the parent of several sub-modes
- ;; but it's also the function that chooses between those submodes.
- ;; To tell the difference between those two cases where the function
- ;; might be called, we check `delay-mode-hooks'.
- ;; (adopted from tex-mode.el)
+ ;; `conf-mode' is the parent of several sub-modes but it's also sometimes
+ ;; abused as the function that chooses between those submodes. They should
+ ;; call `conf-guess-mode' directly, but for historical reasons, we try to
+ ;; accommodate those misuses with this ugly hack.
(if (not delay-mode-hooks)
- ;; try to guess sub-mode of conf-mode based on buffer content
- (let ((unix 0) (win 0) (equal 0) (colon 0) (space 0) (jp 0))
- (save-excursion
- (goto-char (point-min))
- (while (not (eobp))
- (skip-chars-forward " \t\f")
- (cond ((eq (char-after) ?\#) (setq unix (1+ unix)))
- ((eq (char-after) ?\;) (setq win (1+ win)))
- ((eq (char-after) ?\[)) ; nop
- ((eolp)) ; nop
- ((eq (char-after) ?})) ; nop
- ;; recognize at most double spaces within names
- ((looking-at "[^ \t\n=:]+\\(?: ?[^ \t\n=:]+\\)*[ \t]*[=:]")
- (if (eq (char-before (match-end 0)) ?=)
- (setq equal (1+ equal))
- (setq colon (1+ colon))))
- ((looking-at "/[/*]") (setq jp (1+ jp)))
- ((looking-at ".*{")) ; nop
- ((setq space (1+ space))))
- (forward-line)))
- (cond
- ((> jp (max unix win 3)) (conf-javaprop-mode))
- ((> colon (max equal space)) (conf-colon-mode))
- ((> space (max equal colon)) (conf-space-mode))
- ((or (> win unix) (and (= win unix) (eq system-type 'windows-nt)))
- (conf-windows-mode))
- (t (conf-unix-mode))))
-
- (kill-all-local-variables)
- (use-local-map conf-mode-map)
- (setq major-mode 'conf-mode
- mode-name "Conf[?]")
+ ;; Try to guess sub-mode of conf-mode based on buffer content.
+ (conf-guess-mode)
(set (make-local-variable 'font-lock-defaults)
'(conf-font-lock-keywords nil t nil nil))
;; Let newcomment.el decide this for itself.
@@ -438,8 +435,7 @@ conf-mode
;; [section]
(nil "^[ \t]*\\[[ \t]*\\(.+\\)[ \t]*\\]" 1)
;; section { ... }
- (nil "^[ \t]*\\([^=:{} \t\n][^=:{}\n]+\\)[ \t\n]*{" 1)))
- (run-mode-hooks 'conf-mode-hook)))
+ (nil "^[ \t]*\\([^=:{} \t\n][^=:{}\n]+\\)[ \t\n]*{" 1)))))
(defun conf-mode-initialize (comment &optional font-lock)
"Initializations for sub-modes of `conf-mode'.
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1994-97 Ian Jackson.