Fix bug when the scanner does a pushback at the end of input.

src/preparser-api.cc

 // Copyright 2010 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 51 matching lines @@
         pushback_buffer_backing_size_(0) {
     buffer_cursor_ = buffer_end_ = buffer_ + kPushBackSize;
   }
 
   virtual ~InputStreamUTF16Buffer() {
     if (pushback_buffer_backing_ != NULL) {
       DeleteArray(pushback_buffer_backing_);
     }
   }
 
-  virtual void PushBack(uc16 ch) {
+  virtual void PushBack(uc32 ch) {
     ASSERT(pos_ > 0);
+    if (ch == kEndOfInput) {
+      pos_--;
+      return;
+    }
     if (buffer_cursor_ <= pushback_buffer_) {
       // No more room in the current buffer to do pushbacks.
       if (pushback_buffer_end_cache_ == NULL) {
         // We have overflowed the pushback space at the beginning of buffer_.
         // Switch to using a separate allocated pushback buffer.
         if (pushback_buffer_backing_ == NULL) {
           // Allocate a buffer the first time we need it.
           pushback_buffer_backing_ = NewArray<uc16>(kPushBackSize);
           pushback_buffer_backing_size_ = kPushBackSize;
         }
         pushback_buffer_ = pushback_buffer_backing_;
         pushback_buffer_end_cache_ = buffer_end_;
         buffer_end_ = pushback_buffer_backing_ + pushback_buffer_backing_size_;
         buffer_cursor_ = buffer_end_ - 1;
       } else {
         // Hit the bottom of the allocated pushback buffer.
         // Double the buffer and continue.
         uc16* new_buffer = NewArray<uc16>(pushback_buffer_backing_size_ * 2);
         memcpy(new_buffer + pushback_buffer_backing_size_,
                pushback_buffer_backing_,
                pushback_buffer_backing_size_);
         DeleteArray(pushback_buffer_backing_);
         buffer_cursor_ = new_buffer + pushback_buffer_backing_size_;
         pushback_buffer_backing_ = pushback_buffer_ = new_buffer;
         buffer_end_ = pushback_buffer_backing_ + pushback_buffer_backing_size_;
       }
     }
-    pushback_buffer_[buffer_cursor_ - pushback_buffer_- 1] = ch;
+    pushback_buffer_[buffer_cursor_ - pushback_buffer_- 1] =
+        static_cast<uc16>(ch);
     pos_--;
   }
 
  protected:
   virtual bool ReadBlock() {
     if (pushback_buffer_end_cache_ != NULL) {
       buffer_cursor_ = buffer_;
       buffer_end_ = pushback_buffer_end_cache_;
       pushback_buffer_end_cache_ = NULL;
       return buffer_end_ > buffer_cursor_;
@@ skipping 87 matching lines @@
   return PreParserData(size, data);
 }
 
 }  // namespace v8.
 
 
 // Used by ASSERT macros and other immediate exits.
 extern "C" void V8_Fatal(const char* file, int line, const char* format, ...) {
   exit(EXIT_FAILURE);
 }