t/pmc/packfile.t: Warning about invalid Parrot bytecode file

[James E Keenan]

James E Keenan wrote:
> ok 4 - bytecode_major set
> PackFile_unpack: This is not a valid Parrot bytecode file
> ok 5 - set_string_native with invalid data throws
> ok 6 - get_string(uuid)

Here's the relevant source code:

src/packfile.c

  993 PARROT_EXPORT
  994 PARROT_WARN_UNUSED_RESULT
  995 opcode_t
  996 PackFile_unpack(PARROT_INTERP, ARGMOD(PackFile *self),
  997     ARGIN(const opcode_t *packed), size_t packed_size)
  998 {
  999     ASSERT_ARGS(PackFile_unpack)
1000     PackFile_Header * const header = self->header;
1001     const opcode_t         *cursor;
1002     int                     header_read_length;
1003     opcode_t                padding;
1004 #if TRACE_PACKFILE
1005     PackFile        * const pf  = self;
1006 #endif
1007
1008     if (packed_size < PACKFILE_HEADER_BYTES) {
1009         Parrot_io_eprintf(NULL, "PackFile_unpack: "
1010             "Buffer length %d is shorter than PACKFILE_HEADER_BYTES 
%d\n",
1011             packed_size, PACKFILE_HEADER_BYTES);
1012         return 0;
1013     }
1014
1015     self->src  = packed;
1016     self->size = packed_size;
1017
1018     /* Extract the header. */
1019     memcpy(header, packed, PACKFILE_HEADER_BYTES);
1020
1021     /* Ensure the magic is correct. */
1022     if (memcmp(header->magic, "\376PBC\r\n\032\n", 8) != 0) {
1023         Parrot_io_eprintf(NULL, "PackFile_unpack: "
1024             "This is not a valid Parrot bytecode file\n");
1025         return 0;
1026     }