x11: fix reporting shift modifiers for SHIFT-Enter, Space, Tab

refs: https://github.com/wez/wezterm/issues/516

docs/changelog.md

@@ -43,6 +43,7 @@ brief notes about them may accumulate here.
 * New: configure [window_decorations](config/lua/config/window_decorations.md) to remove the title bar and/or window border
 * New: we now bundle [PowerlineExtraSymbols](https://github.com/ryanoasis/powerline-extra-symbols) as a built-in fallback font, so that you can use powerline glyphs with any font without patching the font.
 * Windows: fix the unexpected default behavior of Ctrl-Alt being converted to AltGr for layouts supporting this key, the previous behavior is still possible by enabling the option [`treat_left_ctrlalt_as_altgr`](config/lua/config/treat_left_ctrlalt_as_altgr.md) (to solve [#392](https://github.com/wez/wezterm/issues/392)). Thanks to [@bew](https://github.com/bew)! [#512](https://github.com/wez/wezterm/pull/512)
+* X11: fix an issue where SHIFT-Enter was not recognized [#516](https://github.com/wez/wezterm/issues/516)
 
 ### 20210203-095643-70a364eb
 

window/src/os/x11/keyboard.rs

@@ -138,9 +138,10 @@ impl Keyboard {
         // modifier state.  eg: SHIFT-c in an US layout produces `Char('C')`.
         // So, if we have `Char`, remove SHIFT from the processed modifier
         // state.  Not doing so can produce frustration such as that in
-        // https://github.com/wez/wezterm/issues/394
+        // https://github.com/wez/wezterm/issues/394, but take care to avoid
+        // eliminating it for eg: Enter (https://github.com/wez/wezterm/issues/516)
         let modifiers = match (&kc, raw_modifiers) {
-            (crate::KeyCode::Char(_), mods) => mods - Modifiers::SHIFT,
+            (crate::KeyCode::Char(c), mods) if !c.is_ascii_whitespace() => mods - Modifiers::SHIFT,
             (_, mods) => mods,
         };