This removes the P2SH script verify flag from the various reference test
data since it is now a noop due to the corresponding flag being removed
from the script engine.
This removes the ScriptBip16 flag from the txscript package, changes the
default semantics to always enforce its behavior, and updates all
callers in the repository accordingly.
This change is being made to simplify the script engine code since the
flag has always been active and required by consensus in Decred, so there is
no need to require a flag to conditionally toggle it.
Also, since it is no longer possible to invoke the script engine without
the flag with the clean stack flag, it removes the now unused
ErrInvalidFlags error and associated tests.
It should be noted that the test removed from script_tests.json
specifically dealt with ensuring a signature script that contained
non-data-pushing opcodes was successful when neither the ScriptBip16 or
ScriptVerifySigPushOnly flags were set. Therefore, it is no longer
necessary.
Finally, the P2SH indicator to enable the flag in the test data has been
retained for now in order to keep the logic changes separate.
This updates the data driven transaction script tests to combine the
previously separate valid and invalid test data files into a single file
and adds a field for the expected result. This is a nice improvement
since it means tests can now ensure script failures are due to a
specific expected reason as opposed to only generically detecting
failure as the previous format required.
Since it is possible that the script engine might return more fine
grained errors than that test data expects, the test adapter handles
this by allowing expected errors in the test data to be mapped to
multiple txscript errors.
While performing the conversion, it also adds several tests for the
following areas:
- The test harness itself to ensure the parsing logic, particularly for
the recently added repetition syntax, is working as intended
- All of the opcodes which were converted to NOPs in Decred
to ensure they are also discouraged from use
- All of the reserved opcodes in Decred
