I have some glass glue. As in, when you need to glue two pieces of glass together, this is the glue to use.
It seemed like a good idea. But in practice, nothing glass that has broken has been salvageable or glue-able.
There is a possibility that this is for glueing glass before it’s broken. When you need to attach two pieces of glass, you grab glass glue first.
I just don’t see many cases where you are going to do that. I think there is no good case for glass glue.