[mutter] native: Restore previous EGL state after blitting onto secondary GPU

[Jonas Ådahl <jadahl src gnome org>]

commit ae26cd07740e45ae16a3503004933d1cc295df29
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Apr 19 17:28:07 2018 +0200

    native: Restore previous EGL state after blitting onto secondary GPU
    
    Before we just set it to "none", but this was not enough since various
    calls will depend on not just the context being active, but the main
    rendering surface.
    
    Fixes https://gitlab.gnome.org/GNOME/mutter/issues/21

 cogl/cogl/Makefile.am                      |  2 +-
 cogl/cogl/winsys/cogl-winsys-egl-private.h |  3 +++
 cogl/cogl/winsys/cogl-winsys-egl.c         | 12 ++++++++++++
 src/backends/native/meta-renderer-native.c |  7 +------
 4 files changed, 17 insertions(+), 7 deletions(-)
---
diff --git a/cogl/cogl/Makefile.am b/cogl/cogl/Makefile.am
index ad3dce895..66accf709 100644
--- a/cogl/cogl/Makefile.am
+++ b/cogl/cogl/Makefile.am
@@ -452,7 +452,7 @@ libmutter_cogl_@LIBMUTTER_API_VERSION@_la_LDFLAGS = \
        -avoid-version \
        -export-dynamic \
        -rpath $(mutterlibdir) \
-       -export-symbols-regex 
"^(cogl|_cogl_debug_flags|_cogl_atlas_new|_cogl_atlas_add_reorganize_callback|_cogl_atlas_reserve_space|_cogl_callback|_cogl_util_get_eye_planes_for_screen_poly|_cogl_atlas_texture_remove_reorganize_callback|_cogl_atlas_texture_add_reorganize_callback|_cogl_texture_get_format|_cogl_texture_foreach_sub_texture_in_region|_cogl_texture_set_region|_cogl_profile_trace_message|_cogl_context_get_default|_cogl_framebuffer_get_stencil_bits|_cogl_clip_stack_push_rectangle|_cogl_framebuffer_get_modelview_stack|_cogl_object_default_unref|_cogl_pipeline_foreach_layer_internal|_cogl_clip_stack_push_primitive|_cogl_buffer_unmap_for_fill_or_fallback|_cogl_framebuffer_draw_primitive|_cogl_debug_instances|_cogl_framebuffer_get_projection_stack|_cogl_pipeline_layer_get_texture|_cogl_buffer_map_for_fill_or_fallback|_cogl_texture_can_hardware_repeat|_cogl_pipeline_prune_to_n_layers|_cogl_primitive_draw|test_|unit_test_|_cogl_winsys_glx_get_vtable|_cogl_winsys_egl_xlib_get_
 vtable|_
 
cogl_winsys_egl_get_vtable|_cogl_closure_disconnect|_cogl_onscreen_notify_complete|_cogl_onscreen_notify_frame_sync|_cogl_winsys_egl_renderer_connect_common|_cogl_winsys_error_quark|_cogl_set_error|_cogl_poll_renderer_add_fd|_cogl_poll_renderer_add_idle|_cogl_framebuffer_winsys_update_size|_cogl_winsys_egl_make_current|_cogl_pixel_format_get_bytes_per_pixel).*"
+       -export-symbols-regex 
"^(cogl|_cogl_debug_flags|_cogl_atlas_new|_cogl_atlas_add_reorganize_callback|_cogl_atlas_reserve_space|_cogl_callback|_cogl_util_get_eye_planes_for_screen_poly|_cogl_atlas_texture_remove_reorganize_callback|_cogl_atlas_texture_add_reorganize_callback|_cogl_texture_get_format|_cogl_texture_foreach_sub_texture_in_region|_cogl_texture_set_region|_cogl_profile_trace_message|_cogl_context_get_default|_cogl_framebuffer_get_stencil_bits|_cogl_clip_stack_push_rectangle|_cogl_framebuffer_get_modelview_stack|_cogl_object_default_unref|_cogl_pipeline_foreach_layer_internal|_cogl_clip_stack_push_primitive|_cogl_buffer_unmap_for_fill_or_fallback|_cogl_framebuffer_draw_primitive|_cogl_debug_instances|_cogl_framebuffer_get_projection_stack|_cogl_pipeline_layer_get_texture|_cogl_buffer_map_for_fill_or_fallback|_cogl_texture_can_hardware_repeat|_cogl_pipeline_prune_to_n_layers|_cogl_primitive_draw|test_|unit_test_|_cogl_winsys_glx_get_vtable|_cogl_winsys_egl_xlib_get_
 vtable|_
 
cogl_winsys_egl_get_vtable|_cogl_closure_disconnect|_cogl_onscreen_notify_complete|_cogl_onscreen_notify_frame_sync|_cogl_winsys_egl_renderer_connect_common|_cogl_winsys_error_quark|_cogl_set_error|_cogl_poll_renderer_add_fd|_cogl_poll_renderer_add_idle|_cogl_framebuffer_winsys_update_size|_cogl_winsys_egl_make_current|_cogl_winsys_egl_ensure_current|_cogl_pixel_format_get_bytes_per_pixel).*"
 
 libmutter_cogl_@LIBMUTTER_API_VERSION@_la_SOURCES = $(cogl_sources_c)
 nodist_libmutter_cogl_@LIBMUTTER_API_VERSION@_la_SOURCES = $(BUILT_SOURCES)
diff --git a/cogl/cogl/winsys/cogl-winsys-egl-private.h b/cogl/cogl/winsys/cogl-winsys-egl-private.h
index 8d3ab512b..1db2cd481 100644
--- a/cogl/cogl/winsys/cogl-winsys-egl-private.h
+++ b/cogl/cogl/winsys/cogl-winsys-egl-private.h
@@ -181,6 +181,9 @@ _cogl_winsys_egl_make_current (CoglDisplay *display,
                                EGLSurface read,
                                EGLContext context);
 
+EGLBoolean
+_cogl_winsys_egl_ensure_current (CoglDisplay *display);
+
 #ifdef EGL_KHR_image_base
 EGLImageKHR
 _cogl_egl_create_image (CoglContext *ctx,
diff --git a/cogl/cogl/winsys/cogl-winsys-egl.c b/cogl/cogl/winsys/cogl-winsys-egl.c
index fbd6112d4..73648f663 100644
--- a/cogl/cogl/winsys/cogl-winsys-egl.c
+++ b/cogl/cogl/winsys/cogl-winsys-egl.c
@@ -309,6 +309,18 @@ _cogl_winsys_egl_make_current (CoglDisplay *display,
   return ret;
 }
 
+EGLBoolean
+_cogl_winsys_egl_ensure_current (CoglDisplay *display)
+{
+  CoglDisplayEGL *egl_display = display->winsys;
+  CoglRendererEGL *egl_renderer = display->renderer->winsys;
+
+  return eglMakeCurrent (egl_renderer->edpy,
+                         egl_display->current_draw_surface,
+                         egl_display->current_read_surface,
+                         egl_display->current_context);
+}
+
 static void
 cleanup_context (CoglDisplay *display)
 {
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index c9c3b2eb3..2571cac25 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1911,12 +1911,7 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen *onscreen,
    * context.
    */
   if (egl_context_changed)
-    {
-      _cogl_winsys_egl_make_current (cogl_display,
-                                     EGL_NO_SURFACE,
-                                     EGL_NO_SURFACE,
-                                     EGL_NO_CONTEXT);
-    }
+    _cogl_winsys_egl_ensure_current (cogl_display);
 }
 
 static gboolean