From 78ad4e8f3652b5483c5de868a4ce581ac534d80e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@elmindreda.org>
Date: Tue, 26 May 2020 23:35:40 +0200
Subject: [PATCH] Fix desktop GL header not always being suppressed

If an OpenGL ES header or the glcorearb header is included before the
GLFW header (with no options defined), the legacy OpenGL header will be
implicitly included and the compilation will fail.

This disables the default behavior if we detect any known OpenGL, OpenGL
ES or extension loader inclusion guard macro.

Sources:
 - Khronos headers
 - Windows SDK
 - MinGW
 - MinGW-w64
 - flextGL
 - glad
 - glad2
 - GLEW
 - Galogen
 - gl3w
 - GLXW
 - glbinding
 - Epoxy
 - Glatter
 - glLoadGen
 - Regal
 - GLee
 - OpenGL.framework
 - Debian
 - FreeBSD
 - ANGLE
 - SwiftShader

Related to #1695.

(cherry picked from commit 105cf32e0b05e207d4cd5efa462887569ca2116a)
---
 include/GLFW/glfw3.h | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 88364263..bf854b07 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -193,7 +193,22 @@ extern "C" {
 
  #endif /*__APPLE__*/
 
-#elif !defined(GLFW_INCLUDE_NONE)
+#elif !defined(GLFW_INCLUDE_NONE) && \
+      !defined(__gl_h_) && \
+      !defined(__gles1_gl_h_) && \
+      !defined(__gles2_gl2_h_) && \
+      !defined(__gles2_gl3_h_) && \
+      !defined(__gles2_gl31_h_) && \
+      !defined(__gles2_gl32_h_) && \
+      !defined(__gl_glcorearb_h_) && \
+      !defined(__gl2_h_) /*legacy*/ && \
+      !defined(__gl3_h_) /*legacy*/ && \
+      !defined(__gl31_h_) /*legacy*/ && \
+      !defined(__gl32_h_) /*legacy*/ && \
+      !defined(__glcorearb_h_) /*legacy*/ && \
+      !defined(__GL_H__) /*non-standard*/ && \
+      !defined(__gltypes_h_) /*non-standard*/ && \
+      !defined(__glee_h_) /*non-standard*/
 
  #if defined(__APPLE__)