emacs: Fix applying stickiness to the :notmuch-part property

Previously, we simply called pushnew to add :notmuch-part to the
front-sticky and rear-nonsticky text property lists.  This works if
these are nil or lists, but they can also have the value t, meaning
that all properties are front-sticky/rear-nonsticky.  In this case,
pushnew will signal an error because t is not a list.  We never set
these properties to t ourselves, but since we apply these property
changes over arbitrary renderer output, we have to deal with this
possibility.

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 57719506c92e8cd767977f90849f1c71c0a47ca8..83bb9ad5d02af91496f4fdfd28dc84b84c5cf5c9 100644 (file)
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -846,11 +846,18 @@ If HIDE is non-nil then initially hide this part."
     (notmuch-map-text-property beg (point) :notmuch-part
                               (lambda (v) (or v part)))
     ;; Make :notmuch-part front sticky and rear non-sticky so it stays
-    ;; applied to the beginning of each line when we indent the message.
+    ;; applied to the beginning of each line when we indent the
+    ;; message.  Since we're operating on arbitrary renderer output,
+    ;; watch out for sticky specs of t, which means all properties are
+    ;; front-sticky/rear-nonsticky.
     (notmuch-map-text-property beg (point) 'front-sticky
-                              (lambda (v) (pushnew :notmuch-part v)))
+                              (lambda (v) (if (listp v)
+                                              (pushnew :notmuch-part v)
+                                            v)))
     (notmuch-map-text-property beg (point) 'rear-nonsticky
-                              (lambda (v) (pushnew :notmuch-part v)))))
+                              (lambda (v) (if (listp v)
+                                              (pushnew :notmuch-part v)
+                                            v)))))
 
 (defun notmuch-show-insert-body (msg body depth)
   "Insert the body BODY at depth DEPTH in the current thread."