- Fixed a few small issues exposed by trying to use the playground in r…

…jsf-team#2375

- Also updated the `CHANGELOG.md` to include all of the fixed issues

CHANGELOG.md

@@ -18,7 +18,16 @@ should change the heading of the (upcoming) version to include a major version b
 # 5.0.0-beta-18
 
 # @rjsf/core
-- Updated `MultiSchemaField` to utilize the new `getClosestMatchingOption()` and `sanitizeDataForNewSchema()` functions, fixing [#2944](https://github.com/rjsf-team/react-jsonschema-form/issues/2944), [#3236](https://github.com/rjsf-team/react-jsonschema-form/issues/3236), [#2978](https://github.com/rjsf-team/react-jsonschema-form/issues/2978), and probably others
+- Updated `MultiSchemaField` to utilize the new `getClosestMatchingOption()` and `sanitizeDataForNewSchema()` functions, fixing the following issues:
+  - [#3236](https://github.com/rjsf-team/react-jsonschema-form/issues/3236)
+  - [#2978](https://github.com/rjsf-team/react-jsonschema-form/issues/2978)
+  - [#2944](https://github.com/rjsf-team/react-jsonschema-form/issues/2944)
+  - [#2202](https://github.com/rjsf-team/react-jsonschema-form/issues/2202)
+  - [#2183](https://github.com/rjsf-team/react-jsonschema-form/issues/2183)
+  - [#2086](https://github.com/rjsf-team/react-jsonschema-form/issues/2086)
+  - [#2069](https://github.com/rjsf-team/react-jsonschema-form/issues/2069)
+  - [#1661](https://github.com/rjsf-team/react-jsonschema-form/issues/1661)
+  - And probably others
 
 # @rjsf/utils
 - Added new `getClosestMatchingOption()`, `getFirstMatchingOption()` and `sanitizeDataForNewSchema()` schema-based utility functions

packages/core/src/withTheme.tsx

@@ -28,10 +28,10 @@ export default function withTheme<
       { fields, widgets, templates, ...directProps }: FormProps<T, S, F>,
       ref: ForwardedRef<Form<T, S, F>>
     ) => {
-      fields = { ...themeProps.fields, ...fields };
-      widgets = { ...themeProps.widgets, ...widgets };
+      fields = { ...themeProps?.fields, ...fields };
+      widgets = { ...themeProps?.widgets, ...widgets };
       templates = {
-        ...themeProps.templates,
+        ...themeProps?.templates,
         ...templates,
         ButtonTemplates: {
           ...themeProps?.templates?.ButtonTemplates,

packages/playground/src/app.jsx

@@ -539,7 +539,7 @@ class Playground extends Component {
                 theme={theme}
                 select={this.onThemeSelected}
               />
-              {themes[theme].subthemes && (
+              {themes[theme] && themes[theme].subthemes && (
                 <SubthemeSelector
                   subthemes={themes[theme].subthemes}
                   subtheme={subtheme}