(get_window_cursor_type): Replace BOX cursor on images

with a hollow box cursor if image is larger than 32x32 (or the default
frame font if that is bigger).  Replace any other cursor on images
with hollow box cursor, as redisplay doesn't support bar and hbar
cursors on images.

1 files changed, 24 insertions, 3 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 4144cf51f6a..87fa20fc064 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -21213,9 +21213,30 @@ get_window_cursor_type (w, glyph, width, active_cursor)
   /* Use normal cursor if not blinked off.  */
   if (!w->cursor_off_p)
     {
-      if (glyph != NULL && glyph->type == IMAGE_GLYPH) {
-	if (cursor_type == FILLED_BOX_CURSOR)
-	  cursor_type = HOLLOW_BOX_CURSOR;
+      if (glyph != NULL && glyph->type == IMAGE_GLYPH)
+	{
+	  if (cursor_type == FILLED_BOX_CURSOR)
+	    {
+	      /* Using a block cursor on large images can be very annoying.
+		 So use a hollow cursor for "large" images.  */
+	      struct image *img = IMAGE_FROM_ID (f, glyph->u.img_id);
+	      if (img != NULL && IMAGEP (img->spec))
+		{
+		  /* Arbitrarily, interpret "Large" as >32x32 and >NxN
+		     where N = size of default frame font size.
+		     This should cover most of the "tiny" icons people may use.  */
+		  if (img->width > max (32, WINDOW_FRAME_COLUMN_WIDTH (w))
+		      || img->height > max (32, WINDOW_FRAME_LINE_HEIGHT (w)))
+		    cursor_type = HOLLOW_BOX_CURSOR;
+		}
+	    }
+	  else if (cursor_type != NO_CURSOR)
+	    {
+	      /* Display current only supports BOX and HOLLOW cursors for images.
+		 So for now, unconditionally use a HOLLOW cursor when cursor is
+		 not a solid box cursor.  */
+	      cursor_type = HOLLOW_BOX_CURSOR;
+	    }
       }
       return cursor_type;
     }