I think I found the solution to my problem: I'm comparing to 0 (number) when I should be comparing to "0" (string)? Using: ... if ($hdr(Expires)=="0" || $sel(contact.expires)=="0") { ... Is working as expected. Sorry for the noise! Joel. On Thu, Sep 12, 2019 at 5:50 PM Joel Serrano &lt;joel(a)textplus.com&gt; wrote: > Hello, > > I'm running into what I believe a weird situation when comparing <null> > to 0. > > I have the following lines: > > xlog("L_NOTICE", "DEBUG: sel(contact.expires)=$sel(contact.expires) > - hdr(Expires)=$hdr(Expires)\n"); > if ($hdr(Expires)==0 || $sel(contact.expires)==0) { > xlog("L_NOTICE", "[end] removed user location\n"); > } else { > xlog("L_NOTICE", "[end] saved user location\n"); > } > > I registered with 3 devices, one sends expires as header, another as > contact param, and the last uses both header AND contact param. > > My surprise was this: > > > 1- Both header and contact param: > > Sep 12 19:37:48 csbc01 csbc[8036]: NOTICE: {1 4 REGISTER 02c3ea6ee623916d37532188031017c9@0:0:0:0:0:0:0:0} <script>: DEBUG: sel(contact.expires)=600 - hdr(Expires)=600 > Sep 12 19:37:48 csbc01 csbc[8036]: NOTICE: {1 4 REGISTER 02c3ea6ee623916d37532188031017c9@0:0:0:0:0:0:0:0} <script>: [end] saved user location > > 2- Only contact param: > > Sep 12 19:36:15 csbc01 csbc[8035]: NOTICE: {1 40629 REGISTER f2cbaa53-eabfd633(a)84.121.150.224} <script>: DEBUG: sel(contact.expires)=600 - hdr(Expires)=<null> > Sep 12 19:36:15 csbc01 csbc[8035]: NOTICE: {1 40629 REGISTER f2cbaa53-eabfd633(a)84.121.150.224} <script>: [end] removed user location > > 2- Only header: > > Sep 12 19:29:33 csbc01 csbc[8033]: NOTICE: {1 402 REGISTER 2_1804628355(a)192.168.30.31} <script>: DEBUG: sel(contact.expires)=<null> - hdr(Expires)=3600 > Sep 12 19:29:33 csbc01 csbc[8033]: NOTICE: {1 402 REGISTER 2_1804628355(a)192.168.30.31} <script>: [end] removed user location > > > > I can workaround the header by using is_present_hf() before comparing, I > can also probably parse the $ct to see if it has some Expires in it, but I > really want to know if my understanding is incorrect and I'm doing > something wrong or if this is a bug? > > Thanks! > Joel. > >