Pacify --enable-gcc-warnings when no window system is used.

These warnings found that subscript error, so they seem worthwhile.
* composite.c (char_composable_p): Simplify a bit.
* frame.c (x_set_frame_parameters): Add an IF_LINT.
* frame.c (x_set_horizontal_scroll_bars, x_set_scroll_bar_height):
* frame.h (FRAME_HAS_HORIZONTAL_SCROLL_BARS):
* window.c (set_window_scroll_bars):
Use USE_HORIZONTAL_SCROLL_BARS for simplicity.
* frame.h [! USE_HORIZONTAL_SCROLL_BARS]:
Ignore -Wsuggest-attribute=const.
* window.h (USE_HORIZONTAL_SCROLL_BARS): New macro.
(WINDOW_HAS_HORIZONTAL_SCROLL_BAR): Use it.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/window.h b/src/window.h
index 7e1c7d619b9..ea5dddc9fc8 100644
--- a/src/window.h
+++ b/src/window.h
@@ -785,11 +785,17 @@ wset_next_buffers (struct window *w, Lisp_Object val)
   (WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_LEFT (W)           \
    || WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_RIGHT (W))
 
-/* Say whether horizontal scroll bars are currently enabled for window
-   W.  Horizontal scrollbars exist for toolkit versions only.  */
 #if (defined (HAVE_WINDOW_SYSTEM)                                       \
      && ((defined (USE_TOOLKIT_SCROLL_BARS) && !defined (HAVE_NS))      \
          || defined (HAVE_NTGUI)))
+# define USE_HORIZONTAL_SCROLL_BARS true
+#else
+# define USE_HORIZONTAL_SCROLL_BARS false
+#endif
+
+/* Say whether horizontal scroll bars are currently enabled for window
+   W.  Horizontal scrollbars exist for toolkit versions only.  */
+#if USE_HORIZONTAL_SCROLL_BARS
 #define WINDOW_HAS_HORIZONTAL_SCROLL_BAR(W)                     \
   ((WINDOW_PSEUDO_P (W) || MINI_NON_ONLY_WINDOW_P (W))          \
    ? false                                                      \