Sealed for now.

The seal I'd put on the cement patch I did to the broken floor of our shower had gotten steadily worse and my fear of the work involved in a proper repair has kept me in a frozen state for too long, then it dawned on me that I can do a simple job that may do the trick.
I've used some silicone sealant to stick this old car mat over the broken section. I didn't bother cleaning the top of the mat because it's in a shower and the mud from floodwater should wash off in its own time anyway.

 Sealant on the back of the mat.

A not in focus (sorry about that) photo of the sealant about the repaired section.