[Emacs-diffs] emacs-26 3e39897: Avoid assertion violation under visual-order-cursor-movement

[Eli Zaretskii]

branch: emacs-26
commit 3e39897cd03a10b5d1ac75a89f999943e3dad5c0
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Avoid assertion violation under visual-order-cursor-movement
    
    * src/xdisp.c (Fmove_point_visually): Don't let point exceed the
    BEGV..ZV range.  Signal Beginning of buffer error when there's a
    before-string at BEGV.  (Bug#30787)
---
 src/xdisp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/xdisp.c b/src/xdisp.c
index b003a2f..fb6729c 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -22430,6 +22430,11 @@ Value is the new character position of point.  */)
                    new_pos += (row->reversed_p ? -dir : dir);
                  else
                    new_pos -= (row->reversed_p ? -dir : dir);
+                 new_pos = clip_to_bounds (BEGV, new_pos, ZV);
+                 /* If we didn't move, we've hit BEGV or ZV, so we
+                    need to signal a suitable error.  */
+                 if (new_pos == PT)
+                   break;
                }
              else if (BUFFERP (g->object))
                new_pos = g->charpos;