libucl 0.10.0

What's Changed

New features

• Add a CBOR (RFC 8949) reader and writer: UCL_PARSE_CBOR and UCL_EMIT_CBOR
• Add parser limits for untrusted input: ucl_parser_set_limits() and
  ucl_parser_get_limits() bound depth, element count, allocated bytes, key
  length and string length, and fail with the new UCL_ELIMIT error
• Add UCL_PARSER_SAFE_FLAGS for parsing untrusted input
• Lua: add ucl.untrusted_parser([limits]), parser:set_limits() and
  parser:get_limits()

Behaviour changes

• Lua: push each value of a repeated key as it is, so a [1, 2]; a [3] gives
  {{1, 2}, {3}} rather than {1, 2, 3}
• Reject nesting deeper than 1024 levels in every input format, not only in
  msgpack and CSEXP
• Fail signed includes (.includes, .include(sign=true)) when libucl is
  built without OpenSSL, instead of loading them unverified
• Treat macros as comments with UCL_PARSER_DISABLE_MACRO, as documented,
  instead of failing on them
• Merge only containers into containers with UCL_DUPLICATE_MERGE; a scalar
  after a container follows the priority rules
• Write every value of a repeated key as a JSON or YAML array, also when the
  first value is an array
• Parse a number followed by a comment, or by spaces and the end of the value,
  as a number: a = 1 /* c */ and t = 1s } no longer give strings
• Fail on numbers whose suffix overflows them; ucl_object_toint() clamps
  floats out of the integer range and returns 0 for NaN
• Schema: report errors of the schema itself inside anyOf, oneOf and
  not; reject malformed keywords, non-string or cyclic $ref, empty anyOf
  or oneOf and type arrays with anything but type names
• Keep comments inside an empty object or array inside it when emitting
• Never use zero-copy for files and descriptors, whose mapping libucl releases

Security and robustness

• Fix out-of-bounds reads in the parser, macro arguments and values, msgpack,
  CSEXP, ucl_strnstr, ucl_object_lookup_path_char with a NUL separator and
  the copy of strings with an embedded NUL
• Fix use-after-free on merged duplicate keys and in merges across formats
• Free trees iteratively, so freeing a deeply nested tree cannot exhaust the
  stack
• Check allocation size arithmetic and propagate allocation failures;
  iterating an object no longer allocates
• Fix undefined float-to-integer conversions in the parser, the emitters and
  the Lua binding
• Fix misaligned reads in msgpack and in the bundled mum hash

Bug fixes

• Includes: restore file variables and context after a failed include, remove
  its chunks, release fetched URLs, report a failed fetch of a required URL
  and go on after a skipped .try_include
• Fix ucl_parser_insert_chunk() with chunks that end inside a macro, leave
  frames open, or start with a key in an array
• Fix msgpack negative fixint encoding and decoding and several value bugs
• ucl_object_compare(): compare numbers, string bytes and lengths without
  overflow, and order NaN after every number
• Fix config emitter roundtrip corruption and the placement of comments
• Fix memory leaks on iterator early exit, array merges, nested
  ucl_object_free(), comments left by parse errors and schema $ref fetching
• Fix ucl_object_iter_chk_excpn() prototype to take the iterator, as the
  implementation does
• Fix the pointer returned by ucl_object_pop_keyl()
• Schema: fix additionalProperties and patternProperties matching

Build and tests

• Fix the CMake build when libucl is used as a subproject
• Sync the automake test list with CMake and ignore in-tree build outputs
• Add tests for limits, roundtrips, CBOR, malformed msgpack, CSEXP, schema
  $ref, allocation failures, variables and the Lua binding (ENABLE_LUA)
• Add a CBOR fuzzer