Check for empty repetitions.

src/regexp-macro-assembler.h

 // Copyright 2008 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 117 matching lines @@
   virtual void EmitOrLink(Label* label) = 0;
   virtual void Fail() = 0;
   virtual Handle<Object> GetCode(Handle<String> source) = 0;
   virtual void GoTo(Label* label) = 0;
   // Check whether a register is >= a given constant and go to a label if it
   // is.  Backtracks instead if the label is NULL.
   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0;
   // Check whether a register is < a given constant and go to a label if it is.
   // Backtracks instead if the label is NULL.
   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0;
+  // Check whether a register is != to the current position and go to a
+  // label if it is.

[Erik Corry, 2009/01/08 11:10:16]

Or rather, if it is not?

[Christian Plesner Hansen, 2009/01/08 12:40:49]

Whoops, forgot to update the comment when changing the method.  Fixed.

+  virtual void IfRegisterEqPos(int reg, Label* if_eq) = 0;
   virtual IrregexpImplementation Implementation() = 0;
   virtual void LoadCurrentCharacter(int cp_offset,
                                     Label* on_end_of_input,
                                     bool check_bounds = true,
                                     int characters = 1) = 0;
   virtual void PopCurrentPosition() = 0;
   virtual void PopRegister(int register_index) = 0;
   virtual void PushBacktrack(Label* label) = 0;
   virtual void PushCurrentPosition() = 0;
   virtual void PushRegister(int register_index) = 0;
@@ skipping 44 matching lines @@
   ArraySlice GetBuffer(Vector<T> values);
  private:
   size_t byte_array_size_;
   Handle<ByteArray> current_byte_array_;
   int current_byte_array_free_offset_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_REGEXP_MACRO_ASSEMBLER_H_