Under "How it works", we have steps 2 and 6:
- 2. A new subscript is created from the instruction from the most recent OP_CODESEPARATOR to the end of the script. If there is no OP_CODESEPARATOR the entire script becomes the subscript (hereby referred to as subScript)
- 6. All OP_CODESEPARATORS are removed from subScript
However, doesn't step 6 seem redundant? Vegard
Answer: (sirk390) The comment for step 6. in the bitcoin sources help to understand this (script.cpp:882)
// In case concatenating two scripts ends up with two codeseparators, // or an extra one at the end, this prevents all those possible incompatibilities.
In step 2, only OP_CODESEPARATOR before OP_CHECKSIG are removed. In step OP_CODESEPARATOR after OP_CHECKSIG are also removed.