d8 drops into a shell if no files are passed on command line

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 5a5238011aea88af32d8506d90d1fb3060bd1174..d527315f4cfabae98861adb015012122341ccc12 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -1,4 +1,4 @@
-// Copyright 2009 the V8 project authors. All rights reserved.
+// Copyright 2011 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:
@@ -921,7 +921,7 @@ int Shell::Main(int argc, char* argv[]) {
   // optimization in the last run.
   bool FLAG_stress_opt = false;
   bool FLAG_stress_deopt = false;
-  bool run_shell = (argc == 1);
+  bool FLAG_run_shell = false;
 
   for (int i = 0; i < argc; i++) {
     if (strcmp(argv[i], "--stress-opt") == 0) {
@@ -935,13 +935,17 @@ int Shell::Main(int argc, char* argv[]) {
       FLAG_stress_opt = false;
       FLAG_stress_deopt = false;
     } else if (strcmp(argv[i], "--shell") == 0) {
-      run_shell = true;
+      FLAG_run_shell = true;
       argv[i] = NULL;
     }
   }
 
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
 
+  // Allow SetFlagsFromCommandLine to decrement argc before deciding to
+  // run the shell or not.
+  bool run_shell = FLAG_run_shell || (argc == 1);
+
   Initialize();
 
   int result = 0;