patch 7.4.2347
Problem:    Crash when closing a buffer while Visual mode is active.
            (Dominique Pelle)
Solution:   Adjust the position before computing the number of lines.
            When closing the current buffer stop Visual mode.
diff --git a/src/normal.c b/src/normal.c
index edaa740..92ef575 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -1609,6 +1609,8 @@
 	    oap->start = curwin->w_cursor;
 	}
 
+	/* Just in case lines were deleted that make the position invalid. */
+	check_pos(curwin->w_buffer, &oap->end);
 	oap->line_count = oap->end.lnum - oap->start.lnum + 1;
 
 #ifdef FEAT_VIRTUALEDIT
@@ -9451,10 +9453,7 @@
 #ifdef FEAT_MBYTE
     /* prevent from moving onto a trail byte */
     if (has_mbyte)
-    {
-	check_pos(curwin->w_buffer, &oap->end);
 	mb_adjustpos(curwin->w_buffer, &oap->end);
-    }
 #endif
 
     getvvcol(curwin, &(oap->start), &oap->start_vcol, NULL, &oap->end_vcol);