gl-renderer: check EGL_EXT_platform_base in supports()

An EGL implementation may support client extensions without supporting
EGL_EXT_platform_base. In such a case, we should return 0 to fall back
to the old eglGetDisplay() way.

Cc: Manuel Bachmann <manuel.bachmann@open.eurogiciel.org>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Daniel Stone <daniels@collabora.com>

src/gl-renderer.c

@@ -2213,6 +2213,9 @@ gl_renderer_supports(struct weston_compositor *ec,
 			       extensions);
 	}
 
+	if (!strstr(extensions, "EGL_EXT_platform_base"))
+		return 0;
+
 	snprintf(s, sizeof s, "EGL_KHR_platform_%s", extension_suffix);
 	if (strstr(extensions, s))
 		return 1;
@@ -2225,8 +2228,8 @@ gl_renderer_supports(struct weston_compositor *ec,
 	if (strstr(extensions, s))
 		return 1;
 
-	/* at this point we definitely have some client extensions but
-	 * haven't found the supplied client extension, so chances are it's
+	/* at this point we definitely have some platform extensions but
+	 * haven't found the supplied platform, so chances are it's
 	 * not supported. */
 
 	return -1;