incorrectly reports low ink for VIP version 3 devices

[Tim Waugh]

The device ID parsing code seems to be incorrect in 3.9.8.

For this Device ID I am seeing marker-supply-low-warning state reasons:

MFG:HP;MDL:Officejet Pro
K550;CMD:MLC,PCL,PML,DESKJET,DW-PCL,DYN;CLS:PRINTER;DES:HP Officejet Pro
K550;SN:MY65D5102B;S:028080A880001000810002000300040005031605070518040;Z:031;1284.3M:f7f,f7f;1284.4DL:4d,4e,1;

whereas it seems that the device is reporting no problem.

Here is the code in question:

    if (pSS->GetVIPVersion () == 3)
    {
        for (i = 0; i < numPens; i++, pStr += 4)
        {
            switch (*pStr)
            {
                case '5':
                {
                    if ((*(pStr+1) & 0xf3) > 1)
                    {
                        if (err != NO_ERROR)
                        {
                            err = WARN_LOW_INK_MULTIPLE_PENS;
                        }
                        else
                        {
                            err = WARN_LOW_INK_BLACK;
                        }
                    }
                    break;
                }
...

Here, *(pStr+1) is '0' in each case, i.e. 0x40. This means that the test (0x40 & 0xf3) > 1 is true -- and in fact it will be for any digit.

Shouldn't it be something like this?: *(pStr+1) & 0xf3) > '1'
i.e. with single quotes around the 1 so that the test compares against 0x41 and not 0x01?

The lack of comments leaves me guessing somewhat. ;-)

Original bug report:
  https://bugzilla.redhat.com/show_bug.cgi?id=510926