fix off-by-one truncation detection in VADoRawLog and DoRawLog - #2125
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nabhan06 wants to merge 2 commits into
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fix off-by-one truncation detection in VADoRawLog and DoRawLog#2125nabhan06 wants to merge 2 commits into
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| // A message whose formatted length exactly equals the remaining buffer size is | ||
| // still truncated: vsnprintf() only writes size-1 characters plus the NUL, so | ||
| // truncation must be detected when the would-be length is >= the size, not only | ||
| // when it is strictly greater. With the off-by-one, such a message loses its | ||
| // final character and is emitted without the "(message truncated)" marker (and | ||
| // without the trailing newline). A custom zero-length prefix hook makes the | ||
| // whole raw-log buffer available so the boundary is hit deterministically. |
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This comment is describing the old buggy state, and isn't particularly useful. I'd just delete the whole thing
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Good call, dropped it.
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treat n == size as truncation in VADoRawLog and DoRawLog: vsnprintf writes only size-1 chars at that boundary, so an exactly-buffer-filling raw log message was losing its last byte and being emitted without the
(message truncated)marker or trailing newline, letting a following line concatenate onto it.