Upstream has converted product field disallownew to isactive in their 3.5 bugzilla release as shown in this bug:
this has been merged partially into our branches/upstream3.4 code we need to do full conversion , disallownew still exist in the following places:
[root@localhost upstream-3.4]# grep -rl disallownew .
Interesting story about this one. Actually in upstream 3.4 they are still using products.disallownew and products.isactive is used in their post-3.4 development tree (trunk). So I must have botched up the merge at some point and accidently pulled in this change to our 3.4 internal tree. So my vote is that we just go ahead with switching to products.isactive and then when we rebase later to 3.6, the change will already be implemented.
I have committed the fixes to SVN and closing this. We will create new bugs if we find any functionality issues with product.isactive use.