nixpkgs/pkgs/servers/x11/xorg/xorgserver-dri-path.patch

diff --git a/glx/glxdri.c b/glx/glxdri.c
index 6122653..3f5fc2b 100644
--- a/glx/glxdri.c
+++ b/glx/glxdri.c
@@ -1042,8 +1042,11 @@ __glXDRIscreenProbe(ScreenPtr pScreen)
 	goto handle_error;
     }
 
+    char *real_dri_driver_path = getenv("XORG_DRI_DRIVER_PATH");
+    if (!real_dri_driver_path) real_dri_driver_path = dri_driver_path;
+
     snprintf(filename, sizeof filename, "%s/%s_dri.so",
-             dri_driver_path, driverName);
+             real_dri_driver_path, driverName);
 
     screen->driver = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
     if (screen->driver == NULL) {
diff --git a/glx/glxdri2.c b/glx/glxdri2.c
index ed7fb4c..135b1c8 100644
--- a/glx/glxdri2.c
+++ b/glx/glxdri2.c
@@ -617,8 +617,11 @@ __glXDRIscreenProbe(ScreenPtr pScreen)
 
     __glXInitExtensionEnableBits(screen->glx_enable_bits);
 
-    snprintf(filename, sizeof filename,
-	     "%s/%s_dri.so", dri_driver_path, driverName);
+     char *real_dri_driver_path = getenv("XORG_DRI_DRIVER_PATH");
+     if (!real_dri_driver_path) real_dri_driver_path = dri_driver_path;
+ 
+     snprintf(filename, sizeof filename, "%s/%s_dri.so",
+              real_dri_driver_path, driverName);
 
     screen->driver = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
     if (screen->driver == NULL) {
diff --git a/glx/glxdriswrast.c b/glx/glxdriswrast.c
index 44f658f..8922414 100644
--- a/glx/glxdriswrast.c
+++ b/glx/glxdriswrast.c
@@ -458,8 +458,11 @@ __glXDRIscreenProbe(ScreenPtr pScreen)
     screen->base.swapInterval   = NULL;
     screen->base.pScreen       = pScreen;
 
+    char *real_dri_driver_path = getenv("XORG_DRI_DRIVER_PATH");
+    if (!real_dri_driver_path) real_dri_driver_path = dri_driver_path;
+
     snprintf(filename, sizeof filename,
-	     "%s/%s_dri.so", dri_driver_path, driverName);
+	     "%s/%s_dri.so", real_dri_driver_path, driverName);
 
     screen->driver = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
     if (screen->driver == NULL) {