Header terminated by space causes the entirety of file to be considered start_junk
Seen in f25efe329b05ff817935db5f1be49368856a3868417bbd95a3f34fd8c366dfe6 , header comment is terminated with 0x20, and not EOL.
A possible fix is to allow whitespace to terminate the %PDF-n.m
header, but with a VIOL().
However, relaxing semantics this way might allow for schizophrenic files. TODO: investigate exploitability