master 27658a0a3b: Try to reduce empty areas on GTK when a frame is being resized

[Po Lu]

branch: master
commit 27658a0a3b311ad38b87b9981c6e7b9aaae40728
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Try to reduce empty areas on GTK when a frame is being resized
    
    * src/xterm.c (x_fill_rectangle):
    (x_clear_rectangle, x_draw_image_glyph_string):
    (x_clear_area): Don't use picture if frame background is opaque.
---
 src/xterm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/xterm.c b/src/xterm.c
index b8d0a2b58b..a17b445701 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -1390,6 +1390,7 @@ x_fill_rectangle (struct frame *f, GC gc, int x, int y, 
int width, int height,
 #else
 #if defined HAVE_XRENDER && (RENDER_MAJOR > 0 || (RENDER_MINOR >= 2))
   if (respect_alpha_background
+      && f->alpha_background != 1.0
       && FRAME_DISPLAY_INFO (f)->alpha_bits
       && FRAME_CHECK_XR_VERSION (f, 0, 2))
     {
@@ -1432,6 +1433,7 @@ x_clear_rectangle (struct frame *f, GC gc, int x, int y, 
int width, int height,
 #else
 #if defined HAVE_XRENDER && (RENDER_MAJOR > 0 || (RENDER_MINOR >= 2))
   if (respect_alpha_background
+      && f->alpha_background != 1.0
       && FRAME_DISPLAY_INFO (f)->alpha_bits
       && FRAME_CHECK_XR_VERSION (f, 0, 2))
     {
@@ -4255,6 +4257,7 @@ x_draw_image_glyph_string (struct glyph_string *s)
              XGCValues xgcv;
 #if defined HAVE_XRENDER && (RENDER_MAJOR > 0 || (RENDER_MINOR >= 2))
              if (FRAME_DISPLAY_INFO (s->f)->alpha_bits
+                 && s->f->alpha_background != 1.0
                  && FRAME_CHECK_XR_VERSION (s->f, 0, 2)
                  && FRAME_X_PICTURE_FORMAT (s->f))
                {
@@ -4939,6 +4942,7 @@ x_clear_area (struct frame *f, int x, int y, int width, 
int height)
       x_xr_ensure_picture (f);
       if (FRAME_DISPLAY_INFO (f)->alpha_bits
          && FRAME_X_PICTURE (f) != None
+         && f->alpha_background != 1.0
          && FRAME_CHECK_XR_VERSION (f, 0, 2))
        {
          XRenderColor xc;