From: Stefan Monnier Date: Tue, 9 Apr 2019 22:39:22 +0000 (-0400) Subject: diff-font-lock-syntax: clarify distinction between t and hunk-also X-Git-Tag: emacs-27.0.90~3261^2~18 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=85fbdf027dc03e606c7c4532162148891e41d786;p=emacs.git diff-font-lock-syntax: clarify distinction between t and hunk-also * lisp/vc/diff-mode.el (diff-font-lock-syntax): Rework docstring. (diff-syntax-fontify-hunk): Never use the hunk method when diff-font-lock-syntax is just t. --- diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el index eeac24376e7..8940c7e09a6 100644 --- a/lisp/vc/diff-mode.el +++ b/lisp/vc/diff-mode.el @@ -116,7 +116,7 @@ You can always manually refine a hunk with `diff-refine-hunk'." "If non-nil, diff hunk font-lock includes source language syntax highlighting. This highlighting is the same as added by `font-lock-mode' when corresponding source files are visited normally. -Syntax highlighting is added over diff own highlighted changes. +Syntax highlighting is added over diff-mode's own highlighted changes. If t, the default, highlight syntax only in Diff buffers created by Diff commands that compare files or by VC commands that compare revisions. @@ -126,17 +126,17 @@ For diffs against the working-tree version of a file, the highlighting is based on the current file contents. File-based fontification tries to infer fontification from the compared files. -If revision-based or file-based method fails, use hunk-based method to get -fontification from hunk alone if the value is `hunk-also'. - -If `hunk-only', fontification is based on hunk alone, without full source. +If `hunk-only' fontification is based on hunk alone, without full source. It tries to highlight hunks without enough context that sometimes might result -in wrong fontification. This is the fastest option, but less reliable." +in wrong fontification. This is the fastest option, but less reliable. + +If `hunk-also', use reliable file-based syntax highlighting when available +and hunk-based syntax highlighting otherwise as a fallback." :version "27.1" :type '(choice (const :tag "Don't highlight syntax" nil) - (const :tag "Hunk-based also" hunk-also) (const :tag "Hunk-based only" hunk-only) - (const :tag "Highlight syntax" t))) + (const :tag "Highlight syntax" t) + (const :tag "Allow hunk-based fallback" hunk-also))) (defvar diff-vc-backend nil "The VC backend that created the current Diff buffer, if any.") @@ -2434,67 +2434,61 @@ When OLD is non-nil, highlight the hunk from the old source." (string-to-number (match-string 2 line))) (list (string-to-number line) 1)))) ; One-line diffs (props - (cond - ((and diff-vc-backend (not (eq diff-font-lock-syntax 'hunk-only))) - (let* ((file (diff-find-file-name old t)) - (revision (and file (if (not old) (nth 1 diff-vc-revisions) - (or (nth 0 diff-vc-revisions) - (vc-working-revision file)))))) - (if file - (if (not revision) - ;; Get properties from the current working revision - (when (and (not old) (file-exists-p file) - (file-regular-p file)) - (let ((buf (get-file-buffer (expand-file-name file)))) - ;; Try to reuse an existing buffer - (if buf - (with-current-buffer buf - (diff-syntax-fontify-props nil text line-nb)) - ;; Get properties from the file - (with-temp-buffer - (insert-file-contents file) - (diff-syntax-fontify-props file text line-nb))))) - ;; Get properties from a cached revision - (let* ((buffer-name (format " *diff-syntax:%s.~%s~*" - (expand-file-name file) - revision)) - (buffer (gethash buffer-name - diff-syntax-fontify-revisions))) - (unless (and buffer (buffer-live-p buffer)) - (let* ((vc-buffer (ignore-errors - (vc-find-revision-no-save - (expand-file-name file) revision - diff-vc-backend - (get-buffer-create buffer-name))))) - (when vc-buffer - (setq buffer vc-buffer) - (puthash buffer-name buffer - diff-syntax-fontify-revisions)))) - (when buffer - (with-current-buffer buffer - (diff-syntax-fontify-props file text line-nb))))) - ;; If file is unavailable, get properties from the hunk alone - (setq file (car (diff-hunk-file-names old))) - (with-temp-buffer - (insert text) - (diff-syntax-fontify-props file text line-nb t))))) - ((and diff-default-directory - (not (eq diff-font-lock-syntax 'hunk-only))) - (let ((file (car (diff-hunk-file-names old)))) - (if (and file (file-exists-p file) (file-regular-p file)) - ;; Try to get full text from the file - (with-temp-buffer - (insert-file-contents file) - (diff-syntax-fontify-props file text line-nb)) - ;; Otherwise, get properties from the hunk alone - (with-temp-buffer - (insert text) - (diff-syntax-fontify-props file text line-nb t))))) - ((memq diff-font-lock-syntax '(hunk-also hunk-only)) - (let ((file (car (diff-hunk-file-names old)))) - (with-temp-buffer - (insert text) - (diff-syntax-fontify-props file text line-nb t))))))) + (or + (when (and diff-vc-backend + (not (eq diff-font-lock-syntax 'hunk-only))) + (let* ((file (diff-find-file-name old t)) + (revision (and file (if (not old) (nth 1 diff-vc-revisions) + (or (nth 0 diff-vc-revisions) + (vc-working-revision file)))))) + (when file + (if (not revision) + ;; Get properties from the current working revision + (when (and (not old) (file-exists-p file) + (file-regular-p file)) + (let ((buf (get-file-buffer (expand-file-name file)))) + ;; Try to reuse an existing buffer + (if buf + (with-current-buffer buf + (diff-syntax-fontify-props nil text line-nb)) + ;; Get properties from the file + (with-temp-buffer + (insert-file-contents file) + (diff-syntax-fontify-props file text line-nb))))) + ;; Get properties from a cached revision + (let* ((buffer-name (format " *diff-syntax:%s.~%s~*" + (expand-file-name file) + revision)) + (buffer (gethash buffer-name + diff-syntax-fontify-revisions))) + (unless (and buffer (buffer-live-p buffer)) + (let* ((vc-buffer (ignore-errors + (vc-find-revision-no-save + (expand-file-name file) revision + diff-vc-backend + (get-buffer-create buffer-name))))) + (when vc-buffer + (setq buffer vc-buffer) + (puthash buffer-name buffer + diff-syntax-fontify-revisions)))) + (when buffer + (with-current-buffer buffer + (diff-syntax-fontify-props file text line-nb)))))))) + (let ((file (car (diff-hunk-file-names old)))) + (cond + ((and file diff-default-directory + (not (eq diff-font-lock-syntax 'hunk-only)) + (not diff-vc-backend) + (file-readable-p file) (file-regular-p file)) + ;; Try to get full text from the file. + (with-temp-buffer + (insert-file-contents file) + (diff-syntax-fontify-props file text line-nb))) + ;; Otherwise, get properties from the hunk alone + ((memq diff-font-lock-syntax '(hunk-also hunk-only)) + (with-temp-buffer + (insert text) + (diff-syntax-fontify-props file text line-nb t)))))))) ;; Put properties over the hunk text (goto-char beg)