[mutter] egl: Pass EGL errors via custom error domain

[Jonas Ådahl <jadahl src gnome org>]

commit d8ee96c6cbbbf9b7aac60d0cbd549ff14c0c4517
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Feb 16 17:20:43 2017 +0800

    egl: Pass EGL errors via custom error domain
    
    Introduce META_EGL_ERROR and have the error code be EGL error codes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779112

 src/backends/meta-egl.c |   19 ++++++++++---------
 src/backends/meta-egl.h |    4 ++++
 2 files changed, 14 insertions(+), 9 deletions(-)
---
diff --git a/src/backends/meta-egl.c b/src/backends/meta-egl.c
index 258f5be..ca687c6 100644
--- a/src/backends/meta-egl.c
+++ b/src/backends/meta-egl.c
@@ -70,13 +70,11 @@ struct _MetaEgl
 
 G_DEFINE_TYPE (MetaEgl, meta_egl, G_TYPE_OBJECT)
 
+G_DEFINE_QUARK (-meta-egl-error-quark, meta_egl_error)
+
 static const char *
-get_egl_error_str (void)
+get_egl_error_str (EGLint error_number)
 {
-  EGLint error_number;
-
-  error_number = eglGetError ();
-
   switch (error_number)
     {
     case EGL_SUCCESS:
@@ -133,14 +131,16 @@ get_egl_error_str (void)
 static void
 set_egl_error (GError **error)
 {
+  EGLint error_number;
   const char *error_str;
 
   if (!error)
     return;
 
-  error_str = get_egl_error_str ();
-  g_set_error_literal (error, G_IO_ERROR,
-                       G_IO_ERROR_FAILED,
+  error_number = eglGetError ();
+  error_str = get_egl_error_str (error_number);
+  g_set_error_literal (error, META_EGL_ERROR,
+                       error_number,
                        error_str);
 }
 
@@ -200,7 +200,8 @@ meta_egl_has_extensions (MetaEgl   *egl,
   extensions_str = (const char *) eglQueryString (display, EGL_EXTENSIONS);
   if (!extensions_str)
     {
-      g_warning ("Failed to query string: %s", get_egl_error_str ());
+      g_warning ("Failed to query string: %s",
+                 get_egl_error_str (eglGetError ()));
       return FALSE;
     }
 
diff --git a/src/backends/meta-egl.h b/src/backends/meta-egl.h
index 209cc3e..0a648a6 100644
--- a/src/backends/meta-egl.h
+++ b/src/backends/meta-egl.h
@@ -29,9 +29,13 @@
 #include <EGL/eglext.h>
 #include <glib-object.h>
 
+#define META_EGL_ERROR meta_egl_error_quark ()
+
 #define META_TYPE_EGL (meta_egl_get_type ())
 G_DECLARE_FINAL_TYPE (MetaEgl, meta_egl, META, EGL, GObject)
 
+GQuark meta_egl_error_quark (void);
+
 gboolean meta_egl_has_extensions (MetaEgl   *egl,
                                   EGLDisplay display,
                                   char    ***missing_extensions,