Clarify the doc string of insert-image

* lisp/image.el (insert-image): Mention the effect of a whitespace
image (bug#47240).

diff --git a/lisp/image.el b/lisp/image.el
index b802c1c906f6bf240420aa77ac48e2dff5b7e853..610d020aab5173358b60fe36312a25f201653a7e 100644 (file)
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -603,12 +603,16 @@ means display it in the right marginal area."
 (defun insert-image (image &optional string area slice)
   "Insert IMAGE into current buffer at point.
 IMAGE is displayed by inserting STRING into the current buffer
-with a `display' property whose value is the image.  STRING
-defaults to a single space if you omit it.
+with a `display' property whose value is the image.
+
+STRING defaults to a single space if you omit it, which means
+that the inserted image will behave as whitespace syntactically.
+
 AREA is where to display the image.  AREA nil or omitted means
 display it in the text area, a value of `left-margin' means
 display it in the left marginal area, a value of `right-margin'
 means display it in the right marginal area.
+
 SLICE specifies slice of IMAGE to insert.  SLICE nil or omitted
 means insert whole image.  SLICE is a list (X Y WIDTH HEIGHT)
 specifying the X and Y positions and WIDTH and HEIGHT of image area