(buffer_posn_from_coords): Don't let startp be before BEGV.

diff --git a/src/dispnew.c b/src/dispnew.c
index 206cdb8966170608bd23678f71b1987126a97128..8f010f7795b950dc231404e31b71177aa9f5d759 100644 (file)
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -1504,6 +1504,11 @@ buffer_posn_from_coords (window, col, line)
 
   current_buffer = XBUFFER (window->buffer);
 
+  /* We can't get a correct result in this case,
+     but at least prevent compute_motion from crashing.  */
+  if (startp < BEGV)
+    startp = BEGV;
+
   /* It would be nice if we could use FRAME_CURRENT_GLYPHS (XFRAME
      (window->frame))->bufp to avoid scanning from the very top of
      the window, but it isn't maintained correctly, and I'm not even