Correctly reload theme on :config-reload

The current implementation didn't reload the theme if no no theme was
explicitly configured (so the default theme was used). This commit
brings `refresh_theme` in line with the initialization code.

helix-term/src/application.rs

@@ -397,20 +397,23 @@ impl Application {
 
     /// Refresh theme after config change
     fn refresh_theme(&mut self, config: &Config) -> Result<(), Error> {
-        if let Some(theme) = config.theme.clone() {
-            let true_color = self.true_color();
-            let theme = self
-                .theme_loader
-                .load(&theme)
-                .map_err(|err| anyhow::anyhow!("Failed to load theme `{}`: {}", theme, err))?;
-
-            if true_color || theme.is_16_color() {
-                self.editor.set_theme(theme);
-            } else {
-                anyhow::bail!("theme requires truecolor support, which is not available")
-            }
-        }
+        let true_color = config.editor.true_color || crate::true_color();
+        let theme = config
+            .theme
+            .as_ref()
+            .and_then(|theme| {
+                self.theme_loader
+                    .load(theme)
+                    .map_err(|e| {
+                        log::warn!("failed to load theme `{}` - {}", theme, e);
+                        e
+                    })
+                    .ok()
+                    .filter(|theme| (true_color || theme.is_16_color()))
+            })
+            .unwrap_or_else(|| self.theme_loader.default_theme(true_color));
 
+        self.editor.set_theme(theme);
         Ok(())
     }
 
@@ -435,10 +438,6 @@ impl Application {
         }
     }
 
-    fn true_color(&self) -> bool {
-        self.config.load().editor.true_color || crate::true_color()
-    }
-
     #[cfg(windows)]
     // no signal handling available on windows
     pub async fn handle_signals(&mut self, _signal: ()) {}