From 34ffdc6e3f5f1548ac2ded575cdd0e391cf9b66a Mon Sep 17 00:00:00 2001
From: xndcn <xndchn@gmail.com>
Date: Tue, 29 Dec 2020 22:29:37 +0800
Subject: [PATCH] gl: Fix implicit leaking of shader object

According to OpenGL spec, a shader object will only be flagged
for deletion unless it has been detached; when a program object
is deleted, those shader objects attached to it will be detached
but not deleted unless they have already been flagged for deletion.

So we shall detach a shader object before it is deleted, and delete
it before the program object is deleted best.
---
 demos/gtk-demo/gtkgears.c   | 2 ++
 gdk/gdkgl.c                 | 3 +++
 gsk/gl/gskglshaderbuilder.c | 7 ++-----
 tests/gtkgears.c            | 2 ++
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/demos/gtk-demo/gtkgears.c b/demos/gtk-demo/gtkgears.c
index ba52ddd1b0..1463cbb6b5 100644
--- a/demos/gtk-demo/gtkgears.c
+++ b/demos/gtk-demo/gtkgears.c
@@ -787,6 +787,8 @@ gtk_gears_realize (GtkWidget *widget)
   glLinkProgram(program);
   glGetProgramInfoLog(program, sizeof msg, NULL, msg);
   g_debug ("program info: %s\n", msg);
+  glDetachShader (program, v);
+  glDetachShader (program, f);
   glDeleteShader (v);
   glDeleteShader (f);
 
diff --git a/gdk/gdkgl.c b/gdk/gdkgl.c
index 56dce18333..5ebd2138d8 100644
--- a/gdk/gdkgl.c
+++ b/gdk/gdkgl.c
@@ -107,6 +107,9 @@ make_program (GdkGLContextProgram *program,
 
   glLinkProgram (program->program);
 
+  glDetachShader (program->program, vertex_shader);
+  glDetachShader (program->program, fragment_shader);
+
   glDeleteShader (vertex_shader);
   glDeleteShader (fragment_shader);
 
diff --git a/gsk/gl/gskglshaderbuilder.c b/gsk/gl/gskglshaderbuilder.c
index 1a4ddc301b..75aef60e7d 100644
--- a/gsk/gl/gskglshaderbuilder.c
+++ b/gsk/gl/gskglshaderbuilder.c
@@ -232,6 +232,8 @@ gsk_gl_shader_builder_create_program (GskGLShaderBuilder  *self,
   glBindAttribLocation (program_id, 0, "aPosition");
   glBindAttribLocation (program_id, 1, "vUv");
   glLinkProgram (program_id);
+  glDetachShader (program_id, vertex_id);
+  glDetachShader (program_id, fragment_id);
 
   glGetProgramiv (program_id, GL_LINK_STATUS, &status);
   if (status == GL_FALSE)
@@ -252,14 +254,9 @@ gsk_gl_shader_builder_create_program (GskGLShaderBuilder  *self,
 
       glDeleteProgram (program_id);
       program_id = -1;
-
-      goto out;
     }
 
-  glDetachShader (program_id, vertex_id);
   glDeleteShader (vertex_id);
-
-  glDetachShader (program_id, fragment_id);
   glDeleteShader (fragment_id);
 
 out:
diff --git a/tests/gtkgears.c b/tests/gtkgears.c
index 5f5686c883..2ece67dcf9 100644
--- a/tests/gtkgears.c
+++ b/tests/gtkgears.c
@@ -787,6 +787,8 @@ gtk_gears_realize (GtkWidget *widget)
   glLinkProgram(program);
   glGetProgramInfoLog(program, sizeof msg, NULL, msg);
   g_print ("program info: %s\n", msg);
+  glDetachShader (program, v);
+  glDetachShader (program, f);
   glDeleteShader (v);
   glDeleteShader (f);
 
-- 
2.30.2