[Emacs-diffs] master 792d44b: Preserve face text properties in comint prompt.

[Wolfgang Jenkner]

branch: master
commit 792d44b3c31d2a682607ab8b79ae7d26b7402f41
Author: Wolfgang Jenkner <address@hidden>
Commit: Wolfgang Jenkner <address@hidden>

    Preserve face text properties in comint prompt.
    
    Fixes: debbugs:20084
    
    * lisp/font-lock.el (font-lock--remove-face-from-text-property): New
    function.  Adapted from the previously commented out
    remove-single-text-property.
    Remove previously unused and commented out auxiliary function
    remove-text-property and obsolete comment.
    * lisp/comint.el (comint-output-filter): Use it to remove
    comint-highlight-prompt.
    (comint-snapshot-last-prompt, comint-output-filter): Use
    font-lock-prepend-text-property for comint-highlight-prompt.
    * test/automated/textprop-tests.el: New file.
    (textprop-tests-font-lock--remove-face-from-text-property): New test.
    
    Thus, the original face text property of a prompt "candidate" (the
    last line of an output chunk not ending with a newline) is
    preserved.  This amends the fix for bug#14744.
---
 lisp/ChangeLog                   |   13 ++++++++
 lisp/comint.el                   |   21 ++++++++-----
 lisp/font-lock.el                |   58 +++++++++++++++++--------------------
 test/ChangeLog                   |    5 +++
 test/automated/textprop-tests.el |   57 +++++++++++++++++++++++++++++++++++++
 5 files changed, 115 insertions(+), 39 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 0cc7bc6..b2d431c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,16 @@
+2015-03-27  Wolfgang Jenkner  <address@hidden>
+
+       * font-lock.el (font-lock--remove-face-from-text-property): New
+       function.  Adapted from the previously commented out
+       remove-single-text-property.
+       Remove previously unused and commented out auxiliary function
+       remove-text-property and obsolete comment.
+       * comint.el (comint-output-filter): Use it to remove
+       comint-highlight-prompt.
+       (comint-snapshot-last-prompt, comint-output-filter): Use
+       font-lock-prepend-text-property for comint-highlight-prompt.
+       (Bug#20084)
+
 2015-03-26  Daniel Colascione  <address@hidden>
        * progmodes/python.el
        (python-indent-guess-indent-offset-verbose): New defcustom.
diff --git a/lisp/comint.el b/lisp/comint.el
index b6944da..31649ff 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -1930,10 +1930,10 @@ the start, the cdr to the end of the last prompt 
recognized.")
 Freezes the `font-lock-face' text property in place."
   (when comint-last-prompt
     (with-silent-modifications
-      (add-text-properties
+      (font-lock-prepend-text-property
        (car comint-last-prompt)
        (cdr comint-last-prompt)
-       '(font-lock-face comint-highlight-prompt)))
+       'font-lock-face 'comint-highlight-prompt))
     ;; Reset comint-last-prompt so later on comint-output-filter does
     ;; not remove the font-lock-face text property of the previous
     ;; (this) prompt.
@@ -2084,14 +2084,19 @@ Make backspaces delete the previous character."
                  (add-text-properties prompt-start (point)
                                       '(read-only t front-sticky 
(read-only)))))
              (when comint-last-prompt
-               (remove-text-properties (car comint-last-prompt)
-                                       (cdr comint-last-prompt)
-                                       '(font-lock-face)))
+               (with-silent-modifications
+                 (font-lock--remove-face-from-text-property
+                  (car comint-last-prompt)
+                  (cdr comint-last-prompt)
+                  'font-lock-face
+                  'comint-highlight-prompt)))
              (setq comint-last-prompt
                    (cons (copy-marker prompt-start) (point-marker)))
-             (add-text-properties prompt-start (point)
-                                  '(rear-nonsticky t
-                                    font-lock-face comint-highlight-prompt)))
+             (with-silent-modifications
+               (font-lock-prepend-text-property prompt-start (point)
+                                                'font-lock-face
+                                                'comint-highlight-prompt)
+               (add-text-properties prompt-start (point) '(rear-nonsticky t))))
            (goto-char saved-point)))))))
 
 (defun comint-preinput-scroll-to-bottom ()
diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index 1838a0f..6c8392b 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -1418,37 +1418,33 @@ Optional argument OBJECT is the string or buffer 
containing the text."
       (put-text-property start next prop value object)
       (setq start (text-property-any next end prop nil object)))))
 
-;; For completeness: this is to `remove-text-properties' as `put-text-property'
-;; is to `add-text-properties', etc.
-;;(defun remove-text-property (start end property &optional object)
-;;  "Remove a property from text from START to END.
-;;Argument PROPERTY is the property to remove.
-;;Optional argument OBJECT is the string or buffer containing the text.
-;;Return t if the property was actually removed, nil otherwise."
-;;  (remove-text-properties start end (list property) object))
-
-;; For consistency: maybe this should be called `remove-single-property' like
-;; `next-single-property-change' (not `next-single-text-property-change'), etc.
-;;(defun remove-single-text-property (start end prop value &optional object)
-;;  "Remove a specific property value from text from START to END.
-;;Arguments PROP and VALUE specify the property and value to remove.  The
-;;resulting property values are not equal to VALUE nor lists containing VALUE.
-;;Optional argument OBJECT is the string or buffer containing the text."
-;;  (let ((start (text-property-not-all start end prop nil object)) next prev)
-;;    (while start
-;;      (setq next (next-single-property-change start prop object end)
-;;         prev (get-text-property start prop object))
-;;      (cond ((and (symbolp prev) (eq value prev))
-;;          (remove-text-property start next prop object))
-;;         ((and (listp prev) (memq value prev))
-;;          (let ((new (delq value prev)))
-;;            (cond ((null new)
-;;                   (remove-text-property start next prop object))
-;;                  ((= (length new) 1)
-;;                   (put-text-property start next prop (car new) object))
-;;                  (t
-;;                   (put-text-property start next prop new object))))))
-;;      (setq start (text-property-not-all next end prop nil object)))))
+(defun font-lock--remove-face-from-text-property (start
+                                                 end
+                                                 prop value &optional object)
+  "Remove a specific property value from text from START to END.
+Arguments PROP and VALUE specify the property and value to remove.  The
+resulting property values are not `eq' to VALUE nor lists containing VALUE.
+Optional argument OBJECT is the string or buffer containing the text."
+  (let ((start (text-property-not-all start end prop nil object)) next prev)
+    (while start
+      (setq next (next-single-property-change start prop object end)
+           prev (get-text-property start prop object))
+      (cond ((or (atom prev)
+                (keywordp (car prev))
+                (eq (car prev) 'foreground-color)
+                (eq (car prev) 'background-color))
+            (when (eq value prev)
+              (remove-list-of-text-properties start next (list prop) object)))
+           ((memq value prev)          ;Assume prev is not dotted.
+            (let ((new (remq value prev)))
+              (cond ((null new)
+                     (remove-list-of-text-properties start next (list prop)
+                                                     object))
+                    ((= (length new) 1)
+                     (put-text-property start next prop (car new) object))
+                    (t
+                     (put-text-property start next prop new object))))))
+      (setq start (text-property-not-all next end prop nil object)))))
 
 ;;; End of Additional text property functions.
 
diff --git a/test/ChangeLog b/test/ChangeLog
index a9cad31..30b8841 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,8 @@
+2015-03-27  Wolfgang Jenkner  <address@hidden>
+
+       * automated/textprop-tests.el: New file.
+       (textprop-tests-font-lock--remove-face-from-text-property): New test.
+
 2015-03-24  Michael Albinus  <address@hidden>
 
        * automated/tramp-tests.el (tramp-test18-file-attributes)
diff --git a/test/automated/textprop-tests.el b/test/automated/textprop-tests.el
new file mode 100644
index 0000000..310a7a0
--- /dev/null
+++ b/test/automated/textprop-tests.el
@@ -0,0 +1,57 @@
+;;; textprop-tests.el --- Test suite for text properties.
+
+;; Copyright (C) 2015 Free Software Foundation, Inc.
+
+;; Author: Wolfgang Jenkner <address@hidden>
+;; Keywords: internal
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+
+(ert-deftest textprop-tests-font-lock--remove-face-from-text-property ()
+  "Test `font-lock--remove-face-from-text-property'."
+  (let* ((string "foobar")
+        (stack (list string))
+        (faces '(bold (:foreground "red") underline)))
+    ;; Build each string in `stack' by adding a face to the previous
+    ;; string.
+    (let ((faces (reverse faces)))
+      (push (copy-sequence (car stack)) stack)
+      (put-text-property 0 3 'font-lock-face (pop faces) (car stack))
+      (push (copy-sequence (car stack)) stack)
+      (put-text-property 3 6 'font-lock-face (pop faces) (car stack))
+      (push (copy-sequence (car stack)) stack)
+      (font-lock-prepend-text-property 2 5
+                                      'font-lock-face (pop faces) (car stack)))
+    ;; Check that removing the corresponding face from each string
+    ;; yields the previous string in `stack'.
+    (while faces
+      ;; (message "%S" (car stack))
+      (should (equal-including-properties
+              (progn
+                (font-lock--remove-face-from-text-property 0 6
+                                                           'font-lock-face
+                                                           (pop faces)
+                                                           (car stack))
+                (pop stack))
+              (car stack))))
+    ;; Sanity check.
+    ;; (message "%S" (car stack))
+    (should (and (equal-including-properties (pop stack) string)
+                (null stack)))))