[lejmr]

A NUL byte inside a file ended it. In a comment that happened without an error:

a = 1 # note<NUL>
b = 2

read as {"a":1}, every line below the NUL gone. A file saved as UTF-16 without a byte order mark has a NUL after every ASCII character, so # settings then port = 8080 read as {}. Found by fuzzing (F016); F011 and F013, a NUL in unquoted and triple-quoted text failing with UnexpectedToken, have the same cause.

The spec

• comments.1 (L125): "Anything between // or # and the next newline is considered a comment and ignored", a NUL included.
• unquoted-strings.15 (L280): "unquoted strings have no restriction on control characters, other than the ones listed as forbidden characters", and NUL is not one of them.
• multi-line-strings.1 (L291): "all Unicode characters until a closing """ sequence are used unmodified".
• unquoted-strings.14 (L278): quoted JSON strings may not contain control characters, so a NUL there stays an error.

Changes

• src/Tokenizer.zig: the tokenizer reads a [:0]const u8 and took every 0 byte for the sentinel past the input. Now only the NUL at input.len ends it, checked the way the .eof state already did; one before it is a character in every state. A table test pins all five places it can stand.
• Suite, 482 cases: comments/015 (ignored in a comment, the file goes on), unquoted-strings/031 (kept), 032 (an error in a quoted string), multi-line-strings/010 (kept). typesafe/config does all four as the spec says.
• Oracle protocol: the adapter holds a case in a shell variable, which drops a NUL, so typesafe/config and pyhocon never saw one. suite.encode now sends it as \0 and Oracle.java decodes it; pyhocon's unicode_escape already does.
• CHANGELOG has a Fixed line. It also drops a sentence fix(resolve): a self-reference with nothing below reads the environment #31 left in twice.

A file whose last byte is a stray NUL is now an error (typesafe/config: "Key '' may not be followed by token: end of file") where it read as if the NUL were not there.

Scores

	spec	Java mode
zig-hocon	482/482	423/482
typesafe/config 1.4.9	423/482	482/482
pyhocon 0.3.63	340/482	311/482

zig build test and zig build test-python (100 % coverage) are green.