Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 980M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 389.12
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-11 13:50, hash: rB06312c6d2db8
Short description of error
The Python handler save_pre does not get executed when Blender saves the session recovery file on exit. When add-on's are actively using this handler, they are very likely generating or finalizing data that will be saved along with the file. Skipping over this event while such add-ons are active is likely to cause data loss or strange bugs that will be difficult to track down.
Exact steps for others to reproduce the error
Write a simple script that prints something to the console when save_pre is called, then exit Blender with it active. You can launch Blender from a console window to keep the window open after it exits.