X11: Fix a regression that caused some high res scroll devices to be treated as line based scroll devices

Apparently when running under XWayland, we cant rely on libinput to
detect highres scroll devices. Sigh. Linux input is such a disaster.
Dunno if this will break something else, hopefully not.

Fixes #9646

Author: kovidgoyal

docs/changelog.rst

@@ -178,6 +178,8 @@ Detailed list of changes
 
 - Fix kitty hanging on startup on Intel macs (:iss:`9643`)
 
+- X11: Fix a regression that caused some high res scroll devices to be treated as line based scroll devices (:iss:`9649`)
+
 0.46.0 [2026-03-11]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

glfw/x11_window.c

@@ -29,6 +29,7 @@
 
 #define _GNU_SOURCE
 #include "internal.h"
+#include "math.h"
 #include "backend_utils.h"
 #include "linux_notify.h"
 #include "../kitty/monotonic.h"
@@ -1446,7 +1447,7 @@ handle_xi_motion_event(_GLFWwindow *window, XIDeviceEvent *de) {
             *off = delta;
             if (!d->is_highres) {
                 if (v->increment == 120.) type = GLFW_SCROLL_OFFEST_V120;
-                else {
+                else if (fabs(delta) >= v->increment) {
                     type = GLFW_SCROLL_OFFSET_LINES;
                     if (v->increment != 0) *off /= v->increment;
                 }