After calling FDP::ConsumeRandomLengthString, remaining bytes will never start with '\'
nwellnhof opened this issue · 5 comments
Not sure if this is right place to report this bug, but I noticed that the escape mechanism used by FuzzedDataProvider::ConsumeRandomLengthString consumes all consecutive backslash characters at the end of a string, so that the remaining data can never start with a backslash character (ASCII byte 0x5C). This means that certain fuzz data patterns are impossible to be generated by a subsequent "Consume" operation.
@Dor1s is OOO till end of June, so either this will have to wait or you can submit a patch upstream.
If you have input data ending with N backslash characters, then yes, FDP will consume all of them and return N/2 backslash characters via ConsumeRandomLengthString
In order for remaining data to start with a backslash, the input data should be e.g., \\\A\\something. In such case FDP:: ConsumeRandomLengthString will first create a string containing a single backslash, then it will terminate the string when parsing \A (backslash followed by any non-backslash byte), and the remaining data will be \\something.
Does it make any sense?
Sorry If I misunderstood the issue. In such case, could you please provide an example to clarify?
\\\A
Oh, I didn't realize that A is consumed as well. Sorry for the noise.
No worries, thanks for reaching out!