From 2826f3d42fc9d12b4336145ff647730e9e692945 Mon Sep 17 00:00:00 2001
From: Camilla Berglund <elmindreda@elmindreda.org>
Date: Mon, 15 Feb 2016 15:34:33 +0100
Subject: [PATCH] Check success of MakeCurrent before updating TLS

Fixes #706.
---
 src/egl_context.c | 28 ++++++++++++++++++++--------
 src/glx_context.c | 20 ++++++++++++++++----
 src/wgl_context.c | 21 ++++++++++++++++++---
 3 files changed, 54 insertions(+), 15 deletions(-)

diff --git a/src/egl_context.c b/src/egl_context.c
index ea970708..827ccbfd 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -583,17 +583,29 @@ void _glfwPlatformMakeContextCurrent(_GLFWwindow* window)
 {
     if (window)
     {
-        eglMakeCurrent(_glfw.egl.display,
-                       window->context.egl.surface,
-                       window->context.egl.surface,
-                       window->context.egl.handle);
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            window->context.egl.surface,
+                            window->context.egl.surface,
+                            window->context.egl.handle))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to make context current: %s",
+                            getErrorString(eglGetError()));
+            return;
+        }
     }
     else
     {
-        eglMakeCurrent(_glfw.egl.display,
-                       EGL_NO_SURFACE,
-                       EGL_NO_SURFACE,
-                       EGL_NO_CONTEXT);
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            EGL_NO_SURFACE,
+                            EGL_NO_SURFACE,
+                            EGL_NO_CONTEXT))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to clear current context: %s",
+                            getErrorString(eglGetError()));
+            return;
+        }
     }
 
     _glfwPlatformSetCurrentContext(window);
diff --git a/src/glx_context.c b/src/glx_context.c
index 84c0c701..22ec7e10 100644
--- a/src/glx_context.c
+++ b/src/glx_context.c
@@ -545,12 +545,24 @@ void _glfwPlatformMakeContextCurrent(_GLFWwindow* window)
 {
     if (window)
     {
-        glXMakeCurrent(_glfw.x11.display,
-                       window->context.glx.window,
-                       window->context.glx.handle);
+        if (!glXMakeCurrent(_glfw.x11.display,
+                            window->context.glx.window,
+                            window->context.glx.handle))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "GLX: Failed to make context current");
+            return;
+        }
     }
     else
-        glXMakeCurrent(_glfw.x11.display, None, NULL);
+    {
+        if (!glXMakeCurrent(_glfw.x11.display, None, NULL))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "GLX: Failed to clear current context");
+            return;
+        }
+    }
 
     _glfwPlatformSetCurrentContext(window);
 }
diff --git a/src/wgl_context.c b/src/wgl_context.c
index 55138e70..afc85bab 100644
--- a/src/wgl_context.c
+++ b/src/wgl_context.c
@@ -594,11 +594,26 @@ int _glfwAnalyzeContextWGL(_GLFWwindow* window,
 void _glfwPlatformMakeContextCurrent(_GLFWwindow* window)
 {
     if (window)
-        wglMakeCurrent(window->context.wgl.dc, window->context.wgl.handle);
+    {
+        if (wglMakeCurrent(window->context.wgl.dc, window->context.wgl.handle))
+            _glfwPlatformSetCurrentContext(window);
+        else
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "WGL: Failed to make context current");
+            _glfwPlatformSetCurrentContext(NULL);
+        }
+    }
     else
-        wglMakeCurrent(NULL, NULL);
+    {
+        if (!wglMakeCurrent(NULL, NULL))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "WGL: Failed to clear current context");
+        }
 
-    _glfwPlatformSetCurrentContext(window);
+        _glfwPlatformSetCurrentContext(NULL);
+    }
 }
 
 void _glfwPlatformSwapBuffers(_GLFWwindow* window)