On X11, reload DPI on _XSETTINGS_SETTINGS

This also fixes the deadlock when such reload may happen.

Fixes: #3383
Signed-off-by: John Nunley <dev@notgull.net>
Signed-off-by: Kirill Chibisov <contact@kchibisov.com>

src/platform_impl/linux/x11/util/randr.rs

@@ -38,6 +38,15 @@ pub fn calc_dpi_factor(
 impl XConnection {
     // Retrieve DPI from Xft.dpi property
     pub fn get_xft_dpi(&self) -> Option<f64> {
+        // Try to get it from XSETTINGS first.
+        match self.xsettings_dpi() {
+            Ok(Some(dpi)) => return Some(dpi),
+            Ok(None) => {}
+            Err(err) => {
+                log::warn!("failed to fetch XSettings: {err}");
+            }
+        }
+
         self.database()
             .get_string("Xft.dpi", "")
             .and_then(|s| f64::from_str(s).ok())