Null check in locale resolution (#23301)
diff --git a/packages/flutter/lib/src/widgets/app.dart b/packages/flutter/lib/src/widgets/app.dart
index a6db3e3..15c9de9 100644
--- a/packages/flutter/lib/src/widgets/app.dart
+++ b/packages/flutter/lib/src/widgets/app.dart
@@ -678,6 +678,9 @@
Locale _locale;
Locale _resolveLocale(Locale newLocale, Iterable<Locale> supportedLocales) {
+ if (newLocale == null) {
+ return supportedLocales.first;
+ }
if (widget.localeResolutionCallback != null) {
final Locale locale = widget.localeResolutionCallback(newLocale, widget.supportedLocales);
if (locale != null)
