patch 8.2.4436: crash with weird 'vartabstop' value

Problem:    Crash with weird 'vartabstop' value.
Solution:   Check for running into the end of the line.

src/indent.c

@@ -1338,6 +1338,8 @@ change_indent(
 		new_cursor_col += (*mb_ptr2len)(ptr + new_cursor_col);
 	    else
 		++new_cursor_col;
+	    if (ptr[new_cursor_col] == NUL)
+		break;
 	    vcol += lbr_chartabsize(ptr, ptr + new_cursor_col, (colnr_T)vcol);
 	}
 	vcol = last_vcol;

src/testdir/test_vartabs.vim

@@ -442,4 +442,16 @@ func Test_shiftwidth_vartabstop()
   setlocal shiftwidth& vartabstop& tabstop&
 endfunc
 
+func Test_vartabstop_latin1()
+  let save_encoding = &encoding
+  new
+  set encoding=iso8859
+  silent norm :se 

+  set vartabstop=400
+  norm i00	
+  bwipe!
+  let &encoding = save_encoding
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4436,
 /**/
     4435,
 /**/