linux: Don't insert characters if modifiers other than shift are held (#33424)

Closes #32219 #29666

Release Notes:

- Linux: Now skips insertion of characters when modifiers are held. Before, characters were inserted if there's no match in the keymap.

crates/gpui/src/platform/linux/wayland/window.rs

@@ -699,6 +699,7 @@ impl WaylandWindowStatePtr {
             }
         }
         if let PlatformInput::KeyDown(event) = input {
+            if event.keystroke.modifiers.is_subset_of(&Modifiers::shift()) {
                 if let Some(key_char) = &event.keystroke.key_char {
                     let mut state = self.state.borrow_mut();
                     if let Some(mut input_handler) = state.input_handler.take() {
@@ -709,6 +710,7 @@ impl WaylandWindowStatePtr {
                 }
             }
         }
+    }
 
     pub fn set_focused(&self, focus: bool) {
         self.state.borrow_mut().active = focus;

crates/gpui/src/platform/linux/x11/window.rs

@@ -982,6 +982,8 @@ impl X11WindowStatePtr {
             }
         }
         if let PlatformInput::KeyDown(event) = input {
+            // only allow shift modifier when inserting text
+            if event.keystroke.modifiers.is_subset_of(&Modifiers::shift()) {
                 let mut state = self.state.borrow_mut();
                 if let Some(mut input_handler) = state.input_handler.take() {
                     if let Some(key_char) = &event.keystroke.key_char {
@@ -993,6 +995,7 @@ impl X11WindowStatePtr {
                 }
             }
         }
+    }
 
     pub fn handle_ime_commit(&self, text: String) {
         let mut state = self.state.borrow_mut();