touchpad: revert the clickpad detection mechanism

Use the previous heuristics to detect clickpads where a touchpad was
handled as a clickpad when:

 - The property INPUT_PROP_BUTTONPAD is set
 - The property INPUT_PROP_BUTTONPAD is NOT set but the touchpad only
   has BTN_LEFT

Revert a37d6dcc9c2ec7ebd0d3609e01da1cfcec28db6e:
"touchpad: if we have a right button, let's assume it's not a clickpad"
MR:  https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/614
BUG: https://gitlab.freedesktop.org/libinput/libinput/-/issues/595

Fix #704

Signed-off-by: José Expósito <jose.exposito89@gmail.com>

2 files changed, 14 insertions, 32 deletions

diff --git a/src/evdev-mt-touchpad-buttons.c b/src/evdev-mt-touchpad-buttons.c
index 3ebb5f7a..b0b5ae8e 100644
--- a/src/evdev-mt-touchpad-buttons.c
+++ b/src/evdev-mt-touchpad-buttons.c
@@ -923,6 +923,7 @@ tp_guess_clickpad(const struct tp_dispatch *tp, struct evdev_device *device)
 {
 	bool is_clickpad;
 	bool has_left = libevdev_has_event_code(device->evdev, EV_KEY, BTN_LEFT),
+	     has_middle = libevdev_has_event_code(device->evdev, EV_KEY, BTN_MIDDLE),
 	     has_right = libevdev_has_event_code(device->evdev, EV_KEY, BTN_RIGHT);
 
 	is_clickpad = libevdev_has_property(device->evdev, INPUT_PROP_BUTTONPAD);
@@ -934,19 +935,24 @@ tp_guess_clickpad(const struct tp_dispatch *tp, struct evdev_device *device)
 	 *   single physical button
 	 * - Wacom touch devices have neither left nor right buttons
 	 */
-	if (is_clickpad) {
-		if (has_right) {
-			evdev_log_bug_kernel(device,
-					     "clickpad with right button, assuming it is not a clickpad\n");
-			is_clickpad = false;
-		}
-	} else if (has_left && !has_right &&
-		   (tp->device->model_flags & EVDEV_MODEL_APPLE_TOUCHPAD_ONEBUTTON) == 0) {
+	if (!is_clickpad && has_left && !has_right &&
+	    (tp->device->model_flags & EVDEV_MODEL_APPLE_TOUCHPAD_ONEBUTTON) == 0) {
 		evdev_log_bug_kernel(device,
 				     "missing right button, assuming it is a clickpad.\n");
 		is_clickpad = true;
 	}
 
+	if (has_middle || has_right) {
+		if (is_clickpad)
+			evdev_log_bug_kernel(device,
+					     "clickpad advertising right button\n");
+	} else if (has_left &
+		   !is_clickpad &&
+		   libevdev_get_id_vendor(device->evdev) != VENDOR_ID_APPLE) {
+			evdev_log_bug_kernel(device,
+					     "non clickpad without right button?\n");
+	}
+
 	return is_clickpad;
 }
 
diff --git a/test/test-touchpad-buttons.c b/test/test-touchpad-buttons.c
index b3ff6eca..eccc1eed 100644
--- a/test/test-touchpad-buttons.c
+++ b/test/test-touchpad-buttons.c
@@ -2098,29 +2098,6 @@ START_TEST(touchpad_non_clickpad_detection)
 }
 END_TEST
 
-START_TEST(touchpad_clickpad_detection)
-{
-	struct litest_device *dev;
-	uint32_t methods;
-	int codes[] = {
-		INPUT_PROP_MAX, INPUT_PROP_BUTTONPAD,
-		-1, -1,
-	};
-
-	/* Create a device with LR buttons and INPUT_PROP_BUTTONPAD set - we
-	 * should ignore the property and assume it's a non-clickpad.
-	 * Only way to check that is to verify no click methods are set.
-	 */
-	dev = litest_create_device_with_overrides(LITEST_SYNAPTICS_TOUCHPAD,
-						  "litest Fake Clickpad",
-						  NULL, NULL, codes);
-
-	methods = libinput_device_config_click_get_methods(dev->libinput_device);
-	ck_assert(methods == 0);
-	litest_delete_device(dev);
-}
-END_TEST
-
 TEST_COLLECTION(touchpad_buttons)
 {
 	struct range finger_count = {1, 4};
@@ -2191,6 +2168,5 @@ TEST_COLLECTION(touchpad_buttons)
 	litest_add(clickpad_middleemulation_click_enable_while_down, LITEST_CLICKPAD, LITEST_ANY);
 	litest_add(clickpad_middleemulation_click_disable_while_down, LITEST_CLICKPAD, LITEST_ANY);
 
-	litest_add_no_device(touchpad_clickpad_detection);
 	litest_add_no_device(touchpad_non_clickpad_detection);
 }