Prevent segfault when preparser fails due to lack of argument.

preparser/preparser-process.cc

 // 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:
 //
 //     * 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 182 matching lines @@
 };
 
 
 
 void fail(v8::PreParserData* data, const char* message, ...) {
   va_list args;
   va_start(args, message);
   vfprintf(stderr, message, args);
   va_end(args);
   fflush(stderr);
-  // Print preparser data to stdout.
-  uint32_t size = data->size();
-  fprintf(stderr, "LOG: data size: %u\n", size);
-  if (!WriteBuffer(stdout, data->data(), size)) {
-    perror("ERROR: Writing data");
-    fflush(stderr);
+  if (data != NULL) {
+    // Print preparser data to stdout.
+    uint32_t size = data->size();
+    fprintf(stderr, "LOG: data size: %u\n", size);
+    if (!WriteBuffer(stdout, data->data(), size)) {
+      perror("ERROR: Writing data");
+      fflush(stderr);
+    }
   }
   exit(EXIT_FAILURE);
 }
 
 
 bool IsFlag(const char* arg) {
   // Anything starting with '-' is considered a flag.
   // It's summarily ignored for now.
   return arg[0] == '-';
 }
@@ skipping 140 matching lines @@
   if (data.stack_overflow()) {
     fail(&data, "ERROR: Stack overflow\n");
   }
 
   // Check that the expected exception is thrown, if an exception is
   // expected.
   CheckException(&data, &expects);
 
   return EXIT_SUCCESS;
 }