incorrect generic extension header list

[Cédric Baudoin]

The way 'Generic Extension header List' field in the IR & IR-Dyn Compressed Headers is built for IPv4 Headers and RTP Headers is incorrect.

Although RoHCv1.2.0 does not support List Compression at the moment for IPv4 extension headers and RTP CSRC list; in the case of IPv4 'Dynamic part' (Section 5.7.7.4 of RFC3095) & RTP 'Dynamic part' (Section5.7.7.6 of RFC3095) the 'Generic Extension Header List' field should be packed with 1byte of 'zero' as this field is mandatory and not optional. This is clarified in section 5.1 of the RFC 4815

Without this single byte addition, the IR & IR-Dyn do not conform to completely to RFC3095.

[Julien BERNARD (j-bernard)]

Here is a patch for main branch that resolves the problem.

[Julien BERNARD (j-bernard)]

The previous patch won't be applied on branch 1.2.x in order to keep compatibility with previous releases (format of ROHC packets must not change so that a 1.2.0 compressor may work with a 1.2.1 decompressor for example).
The following patch complete the section entitled "known problems" in the README file of the branch 1.2.x.

[Didier Barvaux (didier-barvaux)]

Do not fix the problem on the 1.2.x branch as it will change the format of some ROHC packets. Compatibility between 1.2.x releases must be preserved. Update the "known problems" section in README to mention the bug. See http://bazaar.launchpad.net/~didier-barvaux/rohc/1.2.x/revision/108

Thank you Julien for the patch.

[Didier Barvaux (didier-barvaux)]

Patch provided by Julien applied on main branch with some minor modifications. See http://bazaar.launchpad.net/~didier-barvaux/rohc/main/revision/115