Avoid assertion violations when line numbers are displayed

* src/xdisp.c (redisplay_window): Clear the window's desired glyph
matrix before calling try_window with the same starting	point.
This avoids assertion violations when switching from a buffer
without line numbers to a buffer with line numbers.  (Bug28710)

diff --git a/src/xdisp.c b/src/xdisp.c
index 141275f15a09e79afd848a1a88a82e0c01a398f4..b14b7daf2b0c4f0b78ead5c83ba69df05153e8aa 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -17036,6 +17036,7 @@ redisplay_window (Lisp_Object window, bool just_this_one_p)
               = try_window_reusing_current_matrix (w)))
        {
          IF_DEBUG (debug_method_add (w, "1"));
+         clear_glyph_matrix (w->desired_matrix);
          if (try_window (window, startp, TRY_WINDOW_CHECK_MARGINS) < 0)
            /* -1 means we need to scroll.
               0 means we need new matrices, but fonts_changed