* Checksum NMEA sentences from the $ delimiter
The PositionLite printWPL() format begins with a CRLF, so the fixed start offset of 1 folded the newline and the $ into the checksum and every sentence went out with a wrong value. Locate the $ instead and stop at the terminator or a \*.
* Clamp truncated writes and harden the remaining fixed buffers
snprintf returns the length it would have written, so a truncated NMEA sentence
made buf + len point past the buffer and bufsz - len underflow into a huge size
for the checksum append. Clamp after each write.
Also pulls in the rest of #11236: the two remaining Dropzone sprintf calls, the
dead strcpy in mt_sprintf that wrote one byte past a zero-size allocation for an
empty format, and the 10-byte errcode buffer that INT32_MIN overflows.
Co-Authored-By: Andrew Yong <me@ndoo.sg>
* Bail out on a zero-sized buffer and cast err for %ld
snprintf writes nothing at all when bufsz is 0, not even a terminator, so the
checksum helper would run strchr over whatever the buffer already held. Return
before touching it.
int32_t is not long on every target, so cast before formatting with %ld.
Co-Authored-By: Andrew Yong <me@ndoo.sg>
* Add NMEA sentence regression tests
Covers checksum computation from the $ delimiter for both printWPL
overloads and printGGA, zero-sized buffers, and truncated buffers down
to one byte.
Co-Authored-By: Andrew Yong <me@ndoo.sg>
* Tighten checksum parsing and pin the WPL fixture checksum
Require exactly two hex digits followed by the sentence terminator, and
assert both WPL overloads against a known checksum instead of comparing
them to each other.
* Bump native suite count to 43
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Co-authored-by: Andrew Yong <me@ndoo.sg>
