[gtk/matthiasc/gltransition-demo: 2/10] gl: Properly report error if shader linking fails

[Matthias Clasen <matthiasc src gnome org>]

commit ec0ad5738c0d8169cfe7652f60a45580d854c9e9
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Sep 18 11:34:14 2020 +0200

    gl: Properly report error if shader linking fails
    
    In gsk_gl_shader_builder_create_program(), if linking fails we
    need to return -1 to indicate error, rather than the old deleted
    program id.

 gsk/gl/gskglshaderbuilder.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gsk/gl/gskglshaderbuilder.c b/gsk/gl/gskglshaderbuilder.c
index a133527784..66f0a3843e 100644
--- a/gsk/gl/gskglshaderbuilder.c
+++ b/gsk/gl/gskglshaderbuilder.c
@@ -188,6 +188,7 @@ gsk_gl_shader_builder_create_program (GskGLShaderBuilder  *self,
       g_free (buffer);
 
       glDeleteProgram (program_id);
+      program_id = -1;
 
       goto out;
     }