wrong bitmask format for insertion/removal schemes of list compression

to fix:

replace near line 1672:

          byte = 0xff;
with
        if (size > 7) byte = 0xff; /* 15 bit mask */
        else byte = 0x7f; /* 7 bit mask */

and so on:
        for(i = 0; i<size && i < 8; i++)
        for(i = 0; i<size && i < 7; i++) // only 7

                        byte &= ~(1 << (7 - i));
                        byte &= ~(1 << (6 - i));

        if (size > 8)
        if (size > 7) // 8 to 15

                for(i = 8; i<size && i < 16; i++)
                for(i = 7; i<size && i < 15; i++)

                                j = i - 8;
                                j = i - 7;

This fix adds the 7bit/15bit mask handling.

Confirmed on the 1.2.x branch.

Confirmed on the 1.3.x branch.

Confirmed on the trunk.

Will not be fixed on the 1.2.x branch as it would break compatibility with previous 1.2.x releases. A note was added to the README file.

Will not be fixed on the 1.3.x branch as it would break compatibility with previous 1.3.x releases. A note was added to the README file. See http://bazaar.launchpad.net/~didier-barvaux/rohc/1.3.x/revision/174

Thanks Klaus for the provided patch! It looks great. However it seems that it does never set the first bit (0 for 7-bit mask, 1 for 15-bit mask) at compressor. Am I missing something?

This was the change, if I remember correct:

- byte = 0xff;
+ byte = (size > 7) ? 0xff : 0x7f;

On size > 7 the bit is 1 (0xff: 1111 1111), for 7 values or less the bit is 0 (0x7f: 0111 1111).

Or more readable:

 if (size > 7) byte = 0xff; /* 15 bit mask */
 else byte = 0x7f; /* 7 bit mask */

OK, you're right for the removal masks. However it seems that the first bit is not set for insertion masks. What do you think of adding the following code for insertion mask?

if(size > 7)
  byte |= 1 << 7;
else
  byte &= 0x7f;

The else part may probably be omitted since byte is initialized to 0.

Fix committed in trunk. See http://bazaar.launchpad.net/~didier-barvaux/rohc/main/revision/300

Thanks to Klaus Warnke for reporting the bug, for the analysis and his patch !

Commit small fixes to avoid build warnings with GCC 4.1, GCC 4.3, GCC 4.4 and GCC 4.6. See http://bazaar.launchpad.net/~didier-barvaux/rohc/main/revision/301.