emacs: Retain text properties when toggling buttons

Previously, we lost any text properties applied to part buttons or
wash buttons when they were toggled because `insert' directly copies
the text properties of the string being inserted.  Fix this by
capturing the properties applied to the button beforehand and
re-applying them after inserting the new text.

2 files changed, 4 insertions, 0 deletions

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index b0a8d8ab..a080134f 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -559,10 +559,12 @@ message at DEPTH in the current thread."
 	     (new-start (button-start button))
 	     (button-label (button-get button :base-label))
 	     (old-point (point))
+	     (properties (text-properties-at (point)))
 	     (inhibit-read-only t))
 	(overlay-put overlay 'invisible (not show))
 	(goto-char new-start)
 	(insert "[ " button-label (if show " ]" " (hidden) ]"))
+	(set-text-properties new-start (point) properties)
 	(let ((old-end (button-end button)))
 	  (move-overlay button new-start (point))
 	  (delete-region (point) old-end))
diff --git a/emacs/notmuch-wash.el b/emacs/notmuch-wash.el
index 8a68819c..8fe91e14 100644
--- a/emacs/notmuch-wash.el
+++ b/emacs/notmuch-wash.el
@@ -104,9 +104,11 @@ lower).")
 	 (overlay (button-get cite-button 'overlay))
 	 (button-label (notmuch-wash-button-label overlay))
 	 (old-point (point))
+	 (properties (text-properties-at (point)))
 	 (inhibit-read-only t))
     (goto-char new-start)
     (insert button-label)
+    (set-text-properties new-start (point) properties)
     (let ((old-end (button-end cite-button)))
       (move-overlay cite-button new-start (point))
       (delete-region (point) old-end))