Parser::Declare follow-up to r38979.

src/parsing/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/parsing/parser.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/ast/ast-expression-rewriter.h"
@@ skipping 1670 matching lines @@
   Variable* variable = scope->DeclareVariable(
       declaration, mode, init, allow_harmony_restrictive_generators(),
       &sloppy_mode_block_scope_function_redefinition, ok);
   if (!*ok) {
     if (declaration_kind == DeclarationDescriptor::NORMAL) {
       ReportMessage(MessageTemplate::kVarRedeclaration,
                     declaration->proxy()->raw_name());
     } else {
       ReportMessage(MessageTemplate::kParamDupe);
     }
+    return nullptr;
   }
   if (sloppy_mode_block_scope_function_redefinition) {
     ++use_counts_[v8::Isolate::kSloppyModeBlockScopedFunctionRedefinition];
   }
   return variable;
 }
 
 // Language extension which is only enabled for source files loaded
 // through the API's extension mechanism.  A native function
 // declaration is resolved by looking up the function through a
@@ skipping 4957 matching lines @@
   node->Print(Isolate::Current());
 }
 #endif  // DEBUG
 
 #undef CHECK_OK
 #undef CHECK_OK_VOID
 #undef CHECK_FAILED
 
 }  // namespace internal
 }  // namespace v8