Distinguish buttons from widgets (bug#34506)

* lisp/button.el (button-at):
* lisp/wid-edit.el (widget-at): Avoid returning a false positive
when looking for a button and finding a widget, or vice versa.
* test/lisp/button-tests.el:
* test/lisp/wid-edit-tests.el: New files.

2 files changed, 9 insertions, 6 deletions

diff --git a/lisp/button.el b/lisp/button.el
index c46f3d9a52b..921e84dfa68 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -382,10 +382,12 @@ Also see `make-text-button'."
 If the button at POS is a text property button, the return value
 is a marker pointing to POS."
   (let ((button (get-char-property pos 'button)))
-    (if (or (overlayp button) (null button))
-        button
-      ;; Must be a text-property button; return a marker pointing to it.
-      (copy-marker pos t))))
+    (and button (get-char-property pos 'category)
+         (if (overlayp button)
+             button
+           ;; Must be a text-property button;
+           ;; return a marker pointing to it.
+           (copy-marker pos t)))))
 
 (defun next-button (pos &optional count-current)
   "Return the next button after position POS in the current buffer.
diff --git a/lisp/wid-edit.el b/lisp/wid-edit.el
index 52c0b5b74d2..b9f98cdc4c7 100644
--- a/lisp/wid-edit.el
+++ b/lisp/wid-edit.el
@@ -1163,8 +1163,9 @@ When not inside a field, signal an error."
 
 (defun widget-at (&optional pos)
   "The button or field at POS (default, point)."
-  (or (get-char-property (or pos (point)) 'button)
-      (widget-field-at pos)))
+  (let ((widget (or (get-char-property (or pos (point)) 'button)
+                    (widget-field-at pos))))
+    (and (widgetp widget) widget)))
 
 ;;;###autoload
 (defun widget-setup ()