The parser may crash instead of returning an error

[dzamlo]

With the input {222222222232222}{} the function defmt_parser::parse(input, defmt_parser::ParserMode::ForwardsCompatible) crash with the message "memory allocation of 3555555555715568 bytes failed" instead of returning an error.

I believe this is an issue and an error should be returned instead of crashing on untrusted input.

I found that using fuzzing. You can found the fuzzing code on https://github.com/dzamlo/defmt/tree/fuzz. The commands used to run the fuzzing is cargo afl build followed by cargo afl fuzz -i in -o out ../target/debug/parser-fuzz-target. The tutorial for the fuzzer I used is available on https://rust-fuzz.github.io/book/afl/tutorial.html.