T28P SIP header of death

[ldardini]

Just found a weirdness on the old Yealink T28P. If you add any kind of SIP header containing three consecutive commas, the phone seems to freeze and doesn't answer to SIP INVITE. Using asterisk dialects, Extension 104-DEVEL will not ring if called this way:

SIPAddHeader(Test: ,,,);
Dial(SIP/104-DEVEL);

It will ring if called this way:

SIPAddHeader(Test: ,a,a,);
Dial(SIP/104-DEVEL);

or if called this way:

SIPAddHeader(Test: ,,);
Dial(SIP/104-DEVEL);