Fix resetting current display when no current context.

Bug swiftshader:65

Change-Id: I8454538d144ed37a56b98c46ed1e88ffdced387e
Reviewed-on: https://swiftshader-review.googlesource.com/10188
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>

src/OpenGL/libEGL/libEGL.cpp

diff --git a/src/OpenGL/libEGL/libEGL.cpp b/src/OpenGL/libEGL/libEGL.cpp
index 979691e..c7a4127 100644
--- a/src/OpenGL/libEGL/libEGL.cpp
+++ b/src/OpenGL/libEGL/libEGL.cpp
@@ -810,7 +810,6 @@
 		UNIMPLEMENTED();   // FIXME
 	}
 
-	egl::setCurrentDisplay(dpy);
 	egl::setCurrentDrawSurface(drawSurface);
 	egl::setCurrentReadSurface(readSurface);
 	egl::setCurrentContext(context);
@@ -856,7 +855,14 @@
 {
 	TRACE("()");
 
-	return success(egl::getCurrentDisplay());
+	egl::Context *context = egl::getCurrentContext();
+
+	if(!context)
+	{
+		return success(EGL_NO_DISPLAY);
+	}
+
+	return success(context->getDisplay());
 }
 
 EGLBoolean QueryContext(EGLDisplay dpy, EGLContext ctx, EGLint attribute, EGLint *value)