bug#21112: 25; Patch: show minibuffer messages with a face

[Juri Linkov]

>>>> I think it might be a good idea to use a different face for these
>>>> temporary messages, but you can currently do this:
>>>>
>>>> (minibuffer-message (propertize "Foo" 'face 'bold))
>>>
>>> So I don't think this is something that we want; closing the bug report.
>>
>> For consistency with isearch messages that are highlighted with the
>> minibuffer-prompt face, minibuffer-message needs to do the same.
>
> [...]
>
>> +    (setq message (apply #'propertize message 
>> minibuffer-message-properties))
>
> But this will overwrite the face properties the caller has set, right?

This patch checks for existing face properties to not overwrite them:

diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index 57702760fb..9a473b6867 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -714,6 +717,9 @@ minibuffer-message
                       (copy-sequence message)
                     (concat " [" message "]")))
     (when args (setq message (apply #'format-message message args)))
+    ;; If not already propertized:
+    (unless (or (text-properties-at 0 message) (next-property-change 0 
message))
+      (setq message (apply #'propertize message 
minibuffer-message-properties)))
     (let ((ol (make-overlay (point-max) (point-max) nil t t))
           ;; A quit during sit-for normally only interrupts the sit-for,
           ;; but since minibuffer-message is used at the end of a command,