Description of problem:
foremost segfaults with broken jpeg file header

Version-Release number of selected component (if applicable):
foremost-1.5.3-1.fc9

gdb backtrace of version 1.5.3 to show the problem:

Program received signal SIGSEGV, Segmentation fault.
0x08053259 in extract_jpeg (s=0x80be008, c_offset=104757349, foundat=0xb7f87848
<Address 0xb7f87848 out of bounds>, buflen=100251, needle=0x8058240,
    f_offset=9961472000) at extract.c:1768
1768                    if (foundat[2] != (unsigned char)'\xff')
(gdb) p *foundat
Cannot access memory at address 0xb7f87848
(gdb) bt
#0  0x08053259 in extract_jpeg (s=0x80be008, c_offset=104757349,
foundat=0xb7f87848 <Address 0xb7f87848 out of bounds>, buflen=100251,
needle=0x8058240,
    f_offset=9961472000) at extract.c:1768
#1  0x080546d7 in extract_file (s=0x80be008, c_offset=104757349,
    foundat=0xb7f6786d
"????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????"...,
buflen=100251, needle=0x8058240, f_offset=9961472000) at extract.c:2338
#2  0x0804e03e in search_chunk (s=0x80be008, buf=0xb1b80008 "\006", i=0x80becd0,
chunk_size=104857600, f_offset=9961472000) at engine.c:462
#3  0x0804e41c in search_stream (s=0x80be008, i=0x80becd0) at engine.c:582
#4  0x0804e72a in process_file (s=0x80be008) at engine.c:675
#5  0x080496ce in main (argc=6, argv=0xbf8fdc18) at main.c:314

See attached patch for fix. (I will send it upstream too.)