Fix https://github.com/bitcoin/bitcoin/issues/6558. In particular, stop
parsing JSON after the first object or array is finished. Check that no
other garbage follows, and fail the parser if it does.
Univalue's parsing of \u escape sequences did not handle NUL characters
correctly. They were, effectively, dropped. The extended test-case
fails with the old code, and is fixed with this patch.
This is a simple utility that provides command line manipulation of
a hex-encoded TX. The utility takes a hex string on the command line
as input, performs zero or more mutations, and outputs a hex string
to standard output.
This utility is also an intentional exercise of the "bitcoin library"
concept. It is designed to require minimal libraries, and works
entirely without need for any RPC or P2P communication.
See "bitcoin-tx --help" for command and options summary.
