cubicweb #3161121 inlined forms have issues with RQL constraints [validation pending]

There is a branch of the code in cw_unrelated_rql which does not processes the constraints because it expects information to be available in __linkto but in inlined forms, that information is hidden in the 'arg' argument of the form.

See http://lists.cubicweb.org/pipermail/cubicweb/2013-September/001444.html and https://bitbucket.org/agurney/cwdemo for a cube illustrating the issue.

prioritynormal
typebug
done in3.20.0
load1.000
load left0.000
closed by#1257e909d25e [forms] consider inline creation form information as linkto info. Closes #3161121
patch[forms] consider inline creation form information as linkto info. Closes #3161121 [applied]