(move_it_vertically): Don't try to fetch byte BEGV-1.

(reseat_at_next_visible_line_start): Likewise (in xassert).

1 files changed, 3 insertions, 1 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 0b34856aa6a..aa81fe7a3db 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -4807,7 +4807,8 @@ reseat_at_next_visible_line_start (it, on_newline_p)
            && indented_beyond_p (IT_CHARPOS (*it), IT_BYTEPOS (*it),
                                  (double) it->selective)) /* iftc */
       {
-        xassert (FETCH_BYTE (IT_BYTEPOS (*it) - 1) == '\n');
+        xassert (IT_BYTEPOS (*it) == BEGV
+                 || FETCH_BYTE (IT_BYTEPOS (*it) - 1) == '\n');
         newline_found_p = forward_to_next_line_start (it, &skipped_p);
       }
 
@@ -6525,6 +6526,7 @@ move_it_vertically (it, dy)
       /* If buffer ends in ZV without a newline, move to the start of
          the line to satisfy the post-condition.  */
       if (IT_CHARPOS (*it) == ZV
+          && ZV > BEGV
           && FETCH_BYTE (IT_BYTEPOS (*it) - 1) != '\n')
         move_it_by_lines (it, 0, 0);
     }