Ensure current active dark modes gets used for manually set themes (#10307)

hassio/src/hassio-main.ts

@@ -113,12 +113,6 @@ export class HassioMain extends SupervisorBaseElement {
           : this.hass.themes.default_theme);
 
       themeSettings = this.hass.selectedTheme;
-      if (themeSettings?.dark === undefined) {
-        themeSettings = {
-          ...this.hass.selectedTheme,
-          dark: this.hass.themes.darkMode,
-        };
-      }
     } else {
       themeName =
         (this.hass.selectedTheme as unknown as string) ||

src/common/dom/apply_themes_on_element.ts

@@ -36,7 +36,15 @@ export const applyThemesOnElement = (
   let cacheKey = selectedTheme;
   let themeRules: Partial<ThemeVars> = {};
 
-  if (themeSettings) {
+  // If there is no explicitly desired dark mode provided, we automatically
+  // use the active one from hass.themes.
+  if (!themeSettings || themeSettings?.dark === undefined) {
+    themeSettings = {
+      ...themeSettings,
+      dark: themes.darkMode,
+    };
+  }
+
   if (themeSettings.dark) {
     cacheKey = `${cacheKey}__dark`;
     themeRules = { ...darkStyles };
@@ -86,7 +94,6 @@ export const applyThemesOnElement = (
       return;
     }
   }
-  }
 
   // Custom theme logic (not relevant for default theme, since it would override
   // the derived calculations from above)

src/layouts/supervisor-error-screen.ts

@@ -91,12 +91,6 @@ class SupervisorErrorScreen extends LitElement {
           : this.hass.themes.default_theme);
 
       themeSettings = this.hass.selectedTheme;
-      if (themeName === "default" && themeSettings?.dark === undefined) {
-        themeSettings = {
-          ...this.hass.selectedTheme,
-          dark: this.hass.themes.darkMode,
-        };
-      }
     } else {
       themeName =
         (this.hass.selectedTheme as unknown as string) ||