Fix completion value of empty catch block in the presence of destructuring.

src/parsing/pattern-rewriter.cc

 // Copyright 2015 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/ast/ast.h"
 #include "src/messages.h"
 #include "src/parsing/parameter-initializer-rewriter.h"
 #include "src/parsing/parser.h"
 
 namespace v8 {
 
 namespace internal {
 
 void Parser::PatternRewriter::DeclareAndInitializeVariables(
     Block* block, const DeclarationDescriptor* declaration_descriptor,
     const DeclarationParsingResult::Declaration* declaration,
     ZoneList<const AstRawString*>* names, bool* ok) {
   PatternRewriter rewriter;
 
+  DCHECK(block->ignore_completion_value());
+
   rewriter.scope_ = declaration_descriptor->scope;
   rewriter.parser_ = declaration_descriptor->parser;
   rewriter.context_ = BINDING;
   rewriter.pattern_ = declaration->pattern;
   rewriter.initializer_position_ = declaration->initializer_position;
   rewriter.block_ = block;
   rewriter.descriptor_ = declaration_descriptor;
   rewriter.names_ = names;
   rewriter.ok_ = ok;
   rewriter.recursion_level_ = 0;
@@ skipping 321 matching lines @@
         factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
         RelocInfo::kNoPosition);
     value = factory()->NewConditional(is_undefined, initializer,
                                       factory()->NewVariableProxy(temp_var),
                                       RelocInfo::kNoPosition);
   }
 
   PatternContext old_context = SetAssignmentContextIfNeeded(initializer);
   int pos = assign->position();
   Block* old_block = block_;
-  block_ = factory()->NewBlock(nullptr, 8, false, pos);
+  block_ = factory()->NewBlock(nullptr, 8, true, pos);
   Variable* temp = nullptr;
   Expression* pattern = assign->target();
   Expression* old_value = current_value_;
   current_value_ = value;
   if (pattern->IsObjectLiteral()) {
     VisitObjectLiteral(pattern->AsObjectLiteral(), &temp);
   } else {
     DCHECK(pattern->IsArrayLiteral());
     VisitArrayLiteral(pattern->AsArrayLiteral(), &temp);
   }
@@ skipping 243 matching lines @@
 NOT_A_PATTERN(TryFinallyStatement)
 NOT_A_PATTERN(UnaryOperation)
 NOT_A_PATTERN(VariableDeclaration)
 NOT_A_PATTERN(WhileStatement)
 NOT_A_PATTERN(WithStatement)
 NOT_A_PATTERN(Yield)
 
 #undef NOT_A_PATTERN
 }  // namespace internal
 }  // namespace v8