Add missing string length check in regexp engine.

src/x64/regexp-macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 335 matching lines @@
   // If length is negative, this code will fail (it's a symptom of a partial or
   // illegal capture where start of capture after end of capture).
   // This must not happen (no back-reference can reference a capture that wasn't
   // closed before in the reg-exp, and we must not generate code that can cause
   // this condition).
 
   // If length is zero, either the capture is empty or it is nonparticipating.
   // In either case succeed immediately.
   __ j(equal, &fallthrough);
 
+  // -----------------------
+  // rdx - Start of capture
+  // rbx - length of capture
+  // Check that there are sufficient characters left in the input.
+  __ movl(rax, rdi);
+  __ addl(rax, rbx);
+  BranchOrBacktrack(greater, on_no_match);
+
   if (mode_ == ASCII) {
     Label loop_increment;
     if (on_no_match == NULL) {
       on_no_match = &backtrack_label_;
     }
 
     __ lea(r9, Operand(rsi, rdx, times_1, 0));
     __ lea(r11, Operand(rsi, rdi, times_1, 0));
     __ addq(rbx, r9);  // End of capture
     // ---------------------
@@ skipping 1161 matching lines @@
   }
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64