Index: clang/include/clang/AST/APValue.h
===================================================================
--- clang/include/clang/AST/APValue.h
+++ clang/include/clang/AST/APValue.h
@@ -508,6 +508,8 @@
     return const_cast<APValue*>(this)->getArrayInitializedElt(I);
   }
   bool hasArrayFiller() const {
+    if (!isArray())
+      return false;
     return getArrayInitializedElts() != getArraySize();
   }
   APValue &getArrayFiller() {
Index: clang/test/SemaCXX/constexpr-array-init.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/constexpr-array-init.cpp
@@ -0,0 +1,19 @@
+
+// RUN: %clang_cc1 -std=c++20 -verify %s
+
+struct Foo {
+  int a; // expected-note {{subobject declared here}}
+  constexpr Foo()
+      : a(get_int()) {
+  }
+
+  constexpr int get_int() {
+    return 5;
+  }
+};
+
+
+static constexpr Foo bar[2][1] = { // expected-error {{constexpr variable 'bar' must be initialized by a constant expression}} \
+                                   // expected-note {{subobject of type 'int' is not initialized}}
+    {{}},
+};