Re: Test to determine character left-overhangs a tab stretch.

[Keith David Bershatsky <esq@lawlist.com>]

Thank you Eli for helping out with this particular issue.  I think the problem is that first_glyph->type (in the following test) is sometimes invalid and that is what causes the crash.  The test is designed to skip over the area of code when a tab stretch would normally be drawn anew due to the next glyph having a left overhang.

Last Commit : Tue Nov 13 22:01:57 2018 +0200
            : Eli Zaretskii <eliz@gnu.org>
            : 4a5a17507fe1e12ee02c174350edc479fb01ac01
            : Fix recent change in fileio.c

diff --git a/src/xdisp.c b/src/xdisp.c
index fa7691c..198a516 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -26841,7 +26841,45 @@ draw_glyphs (struct window *w, int x, struct glyph_row *row,
 	 prepended must be drawn because the first glyph string
 	 draws over it.  */
       i = left_overwritten (head);
-      if (i >= 0)
+
+
+/* *************************************************************************** */
+/* MULTIPLE CURSORS */
+
+      bool skip_p = false;
+      int beg = i;
+
+      if (hl == DRAW_CURSOR)
+        while (beg < start)
+          {
+            struct glyph *first_glyph = (row)->glyphs[area] + beg;
+            if (first_glyph != NULL
+                && first_glyph->type != NULL)
+              {
+                 switch (first_glyph->type)
+                {
+                  case CHAR_GLYPH:
+                    break;
+                  case COMPOSITE_GLYPH:
+                    break;
+                  case STRETCH_GLYPH:
+                    {
+                      skip_p = true;
+                      break;
+                    }
+                  case IMAGE_GLYPH:
+                    break;
+                }
+              }
+            beg += 1;
+          }
+
+      if (i >= 0
+          && !skip_p)
+
+/* *************************************************************************** */
+
+
 	{
 	  enum draw_glyphs_face overlap_hl;