When something didn't fit, the formatters skipped it silently, closing
brackets included, and clients got malformed JSON. Two writes could
also go past the buffer:
- AsyncJsonResp flushed when full and then wrote the value without
checking again, so a value bigger than the whole buffer overflowed.
It is now streamed straight out instead.
- JsonSockEvent::closeEvent added the closing ] when only one byte was
left, putting the terminator one byte past the buffer.
The formatters now set an overflowed() flag and log an error, and a
socket event that overflowed is logged and not sent.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Tests BufferedJsonFormatter output: nesting and commas, number and bool
values, skipped null strings and escaping. A canary after the buffer
catches writes past its end.
Three fail: control characters other than \b\f\n\r\t aren't escaped,
calcEscapedLength skips the first character, and so a value starting
with an escaped character can be written one byte past the buffer.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
