Fix replacing optional fields

This fixes an issue with the default `SerdeReplace` implementation where
it would never recurse through options but always replace the entire
option with the new value.

Closes #7518.

1 files changed, 10 insertions, 0 deletions

diff --git a/alacritty/src/config/ui_config.rs b/alacritty/src/config/ui_config.rs
index f4f67cb6..21059734 100644
--- a/alacritty/src/config/ui_config.rs
+++ b/alacritty/src/config/ui_config.rs
@@ -1,9 +1,11 @@
 use std::cell::RefCell;
 use std::collections::HashMap;
+use std::error::Error;
 use std::fmt::{self, Formatter};
 use std::path::PathBuf;
 use std::rc::Rc;
 
+use alacritty_config::SerdeReplace;
 use alacritty_terminal::term::Config as TermConfig;
 use alacritty_terminal::tty::{Options as PtyOptions, Shell};
 use log::{error, warn};
@@ -656,6 +658,14 @@ impl From<Program> for Shell {
     }
 }
 
+impl SerdeReplace for Program {
+    fn replace(&mut self, value: toml::Value) -> Result<(), Box<dyn Error>> {
+        *self = Self::deserialize(value)?;
+
+        Ok(())
+    }
+}
+
 pub(crate) struct StringVisitor;
 impl<'de> serde::de::Visitor<'de> for StringVisitor {
     type Value = String;