test: Add a test using GLX_EXT_create_context_es2_profile.

This is based on a bug report from Steinar H. Gunderson about using
GLES3 with SDL and epoxy.
diff --git a/test/.gitignore b/test/.gitignore
index f771a27..f280858 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -5,6 +5,7 @@
 egl_gles1_without_glx
 egl_gles2_without_glx
 glx_beginend
+glx_gles2
 glx_glxgetprocaddress_nocontext
 glx_has_extension_nocontext
 glx_public_api
diff --git a/test/Makefile.am b/test/Makefile.am
index e9c4676..a4b9fd7 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -64,6 +64,7 @@
 
 XFAIL_TESTS = \
         egl_and_glx_different_pointers_egl_glx \
+        glx_gles2 \
 	$()
 
 check_PROGRAMS = $(TESTS)
@@ -94,6 +95,7 @@
 endif
 
 GLX_TESTS = \
+	glx_gles2 \
 	glx_beginend \
 	glx_public_api \
 	glx_public_api_core \
@@ -143,6 +145,10 @@
 
 glx_beginend_LDADD = $(EPOXY) libglx_common.la $(GL_LIBS) $(X11_LIBS)
 
+glx_gles2_SOURCES = glx_gles2.c dlwrap.c dlwrap.h
+glx_gles2_LDFLAGS = -rdynamic
+glx_gles2_LDADD = $(EPOXY) libglx_common.la $(X11_LIBS) -ldl
+
 glx_public_api_LDADD = $(EPOXY) libglx_common.la $(X11_LIBS)
 
 glx_public_api_core_LDADD = $(EPOXY) libglx_common.la $(X11_LIBS)
diff --git a/test/glx_gles2.c b/test/glx_gles2.c
new file mode 100644
index 0000000..969d26b
--- /dev/null
+++ b/test/glx_gles2.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/**
+ * @file glx_gles2.c
+ *
+ * Catches a bug where a GLES2 context using
+ * GLX_EXT_create_context_es2_profile would try to find the symbols in
+ * libGLESv2.so.2 instead of libGL.so.1.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <err.h>
+#include "epoxy/gl.h"
+#include "epoxy/glx.h"
+#include <X11/Xlib.h>
+
+#include "glx_common.h"
+
+static Display *dpy;
+
+GLuint
+override_GLES2_glCreateShader(GLenum target);
+
+GLuint
+override_GLES2_glCreateShader(GLenum target)
+{
+    return 0;
+}
+
+void
+override_GLES2_glGenQueries(GLsizei n, GLuint *ids);
+
+void
+override_GLES2_glGenQueries(GLsizei n, GLuint *ids)
+{
+    int i;
+    for (i = 0; i < n; i++)
+        ids[i] = 0;
+}
+
+int
+main(int argc, char **argv)
+{
+    bool pass = true;
+    XVisualInfo *vis;
+    Window win;
+    GLXContext ctx;
+    GLXFBConfig config;
+    int context_attribs[] = {
+        GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_ES2_PROFILE_BIT_EXT,
+        GLX_CONTEXT_MAJOR_VERSION_ARB, 2,
+        GLX_CONTEXT_MINOR_VERSION_ARB, 0,
+        0
+    };
+    GLuint shader;
+
+    dpy = get_display_or_skip();
+
+    if (!epoxy_has_glx_extension(dpy, 0, "GLX_EXT_create_context_es2_profile"))
+        errx(77, "Test requires GLX_EXT_create_context_es2_profile");
+
+    vis = get_glx_visual(dpy);
+    config = get_fbconfig_for_visinfo(dpy, vis);
+    win = get_glx_window(dpy, vis, false);
+
+    ctx = glXCreateContextAttribsARB(dpy, config, NULL, true,
+                                     context_attribs);
+
+    glXMakeCurrent(dpy, win, ctx);
+
+    if (epoxy_is_desktop_gl()) {
+        errx(1, "GLES2 context creation made a desktop context\n");
+    }
+
+    if (epoxy_gl_version() < 20) {
+        errx(1, "GLES2 context creation made a version %f context\n",
+             epoxy_gl_version() / 10.0f);
+    }
+
+    /* Test using an entrypoint that's in GLES2, but not the desktop GL ABI. */
+    shader = glCreateShader(GL_FRAGMENT_SHADER);
+    if (shader == 0)
+        errx(1, "glCreateShader() failed\n");
+    glDeleteShader(shader);
+
+    if (epoxy_gl_version() >= 30) {
+        GLuint q = 0;
+
+        glGenQueries(1, &q);
+        if (!q)
+            errx(1, "glGenQueries() failed\n");
+        glDeleteQueries(1, &q);
+    }
+
+    return pass != true;
+}