PR diagnostic/68899: fix read-beyond-buffer when printing very wide source lines

gcc/ChangeLog:
	PR diagnostic/68899
	* diagnostic-show-locus.c (layout::print_source_line): Move x
	offset of line until after call to
	get_line_width_without_trailing_whitespace.

From-SVN: r232465

gcc/ChangeLog

+2016-01-15  David Malcolm  <dmalcolm@redhat.com>
+
+	PR diagnostic/68899
+	* diagnostic-show-locus.c (layout::print_source_line): Move x
+	offset of line until after call to
+	get_line_width_without_trailing_whitespace.
+
 2016-01-15  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/69270

gcc/diagnostic-show-locus.c

@@ -524,14 +524,13 @@ layout::print_source_line (int row, line_bounds *lbounds_out)
   if (!line)
     return false;
 
-  line += m_x_offset;
-
   m_colorizer.set_normal_text ();
 
   /* We will stop printing the source line at any trailing
      whitespace.  */
   line_width = get_line_width_without_trailing_whitespace (line,
 							   line_width);
+  line += m_x_offset;
 
   pp_space (m_pp);
   int first_non_ws = INT_MAX;