From a785ab9e659db112807ced91662fa4c8bd48ee7b Mon Sep 17 00:00:00 2001
From: Volodymyr Zolotopupov <zvova7890@gmail.com>
Date: Wed, 10 Jul 2024 03:00:08 +0300
Subject: [PATCH] Use the udev "uniq" attribute when generating the device GUID

It helps to avoid duplicate GUIDs when connecting two similar joysticks.
---
 src/core/jstick.c         | 9 +++++++++
 src/core/jstick.h         | 1 +
 src/gui/linux/os_jstick.c | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/src/core/jstick.c b/src/core/jstick.c
index 9457c778a..587d56a86 100644
--- a/src/core/jstick.c
+++ b/src/core/jstick.c
@@ -154,6 +154,15 @@ void js_guid_create(_js_device *jdev) {
 		(*(word + 5)) = jdev->usb.product_id - 300;
 		(*(word + 6)) = jdev->usb.version;
 		(*(word + 7)) = jdev->usb.version - 400;
+
+		BYTE *byte = (BYTE *)&word[2];
+		int idx = 0;
+		for (const char *s = jdev->uniq; *s; ++s) {
+			byte[idx++] ^= *s;
+			if (idx > 11) {
+				idx = 0;
+			}
+		}
 	} else {
 		word += 2;
 		memcpy((char *)word, (char *)jdev->desc, sizeof(jdev->guid.data) - 4);
diff --git a/src/core/jstick.h b/src/core/jstick.h
index 5e070ea25..ad51726f6 100644
--- a/src/core/jstick.h
+++ b/src/core/jstick.h
@@ -165,6 +165,7 @@ typedef struct _js_device {
 	// comuni
 	enum _js_gamepad_type type;
 	uTCHAR desc[128];
+	uTCHAR uniq[128];
 	_js_info info;
 	_js_data data;
 	_input_guid guid;
diff --git a/src/gui/linux/os_jstick.c b/src/gui/linux/os_jstick.c
index d3d834e4a..4b140c995 100644
--- a/src/gui/linux/os_jstick.c
+++ b/src/gui/linux/os_jstick.c
@@ -73,12 +73,15 @@ void js_os_jdev_open(_js_device *jdev, void *arg) {
 			const char *vid = udev_device_get_sysattr_value(udevd, "id/vendor");
 			const char *ver = udev_device_get_sysattr_value(udevd, "id/version");
 			const char *name = udev_device_get_sysattr_value(udevd, "name");
+			const char *uniq = udev_device_get_sysattr_value(udevd, "uniq");
 
 			jdev->usb.bustype = strtoul(btype, NULL, 16);
 			jdev->usb.vendor_id = strtoul(vid, NULL, 16);
 			jdev->usb.product_id = strtoul(pid, NULL, 16);
 			jdev->usb.version = strtoul(ver, NULL, 16);
+
 			ustrncpy(jdev->desc, name, usizeof(jdev->desc) - 1);
+			ustrncpy(jdev->uniq, uniq, usizeof(jdev->uniq) - 1);
 		} else {
 			return;
 		}