Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -15314,8 +15314,9 @@
   Expr::EvalResult Eval;
   Eval.Diag = &Notes;
   ConstantExpr *CE = Candidate.getPointer();
-  if (!CE->EvaluateAsConstantExpr(Eval, Expr::EvaluateForCodeGen,
-                                  SemaRef.getASTContext(), true)) {
+  bool Result = CE->EvaluateAsConstantExpr(Eval, Expr::EvaluateForCodeGen,
+                                           SemaRef.getASTContext(), true);
+  if (!Result || !Notes.empty()) {
     Expr *InnerExpr = CE->getSubExpr()->IgnoreImplicit();
     if (auto *FunctionalCast = dyn_cast<CXXFunctionalCastExpr>(InnerExpr))
       InnerExpr = FunctionalCast->getSubExpr();
Index: clang/test/SemaCXX/cxx2a-consteval.cpp
===================================================================
--- clang/test/SemaCXX/cxx2a-consteval.cpp
+++ clang/test/SemaCXX/cxx2a-consteval.cpp
@@ -342,6 +342,14 @@
 
 namespace alloc {
 
+consteval int f() {
+  int *A = new int(0);
+// expected-note@-1+ {{allocation performed here was not deallocated}}
+  return *A;
+}
+
+int i1 = f(); // expected-error {{is not a constant expression}}
+
 struct A {
   int* p = new int(42);
   // expected-note@-1+ {{heap allocation performed here}}