Index: clang/lib/Sema/IdentifierResolver.cpp
===================================================================
--- clang/lib/Sema/IdentifierResolver.cpp
+++ clang/lib/Sema/IdentifierResolver.cpp
@@ -121,7 +121,8 @@
       // of the controlled statement.
       //
       assert(S->getParent() && "No TUScope?");
-      if (S->getParent()->getFlags() & Scope::ControlScope) {
+      if ((S->getParent()->getFlags() & Scope::ControlScope) &&
+          !(S->getFnParent()->getFlags() & Scope::BlockScope)) {
         S = S->getParent();
         if (S->isDeclScope(D))
           return true;
Index: clang/test/Misc/scope.cpp
===================================================================
--- /dev/null
+++ clang/test/Misc/scope.cpp
@@ -0,0 +1,10 @@
+// RUN: not %clang_cc1 -c -std=c++17 -verify %s
+int test() {
+  if (int foo = [&]() { // expected-error{{redefinition of 'foo'}}
+        int foo = 0;
+        return foo;
+      }();
+      foo) {
+    return 0;
+  }
+}
\ No newline at end of file