[Mesa-stable] [PATCH] egl/main: Fix eglMakeCurrent when releasing context from current thread.

[Chad Versace]

From: Beren Minor <beren.minor at gmail.com>

EGL 1.4 Specification says that
eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)
can be used to release the current thread's ownership on the surfaces
and context.

MESA's egl implementation was only accepting the parameters when the
KHR_surfaceless_context extension is supported.

[chadv] Add quote from the EGL 1.4 spec.
Cc: "10,1, 10.2" <mesa-stable at lists.freedesktop.org>
Reviewed-by: Chad Versace <chad.versace at linux.intel.com>
---

This is commit 0ca0d5743fb42a956289a87efd4c8fcda88cf93a on master.

 src/egl/main/eglapi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index 27d0802..7846814 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -524,8 +524,12 @@ eglMakeCurrent(EGLDisplay dpy, EGLSurface draw, EGLSurface read,
    if (!context && ctx != EGL_NO_CONTEXT)
       RETURN_EGL_ERROR(disp, EGL_BAD_CONTEXT, EGL_FALSE);
    if (!draw_surf || !read_surf) {
-      /* surfaces may be NULL if surfaceless */
-      if (!disp->Extensions.KHR_surfaceless_context)
+      /* From the EGL 1.4 (20130211) spec:
+       *
+       *    To release the current context without assigning a new one, set ctx
+       *    to EGL_NO_CONTEXT and set draw and read to EGL_NO_SURFACE.
+       */
+      if (!disp->Extensions.KHR_surfaceless_context && ctx != EGL_NO_CONTEXT)
          RETURN_EGL_ERROR(disp, EGL_BAD_SURFACE, EGL_FALSE);
 
       if ((!draw_surf && draw != EGL_NO_SURFACE) ||
-- 
2.0.0