Operating system: Kubuntu 18.10, 4.18.0-22-generic #23-Ubuntu SMP Tue Jun 4 20:22:46 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Graphics card: NVIDIA Corporation GP106 [GeForce GTX 1060 6GB] (rev a1)
Broken: 2.80, 9c5d54bfaf48, 2019-06-08 13:24

• open blender with blank profile
• use shift-d to make several duplicates of default cube
• in outliner, shift-click to select several cubes
• drag one of them to another cube, hold shift
• only one object is parented, instead of all of them

This contradicts the behavior of ctrl-p in the viewport, the outliner tooltip which says "Drop to set parent / Objects", and the functionality implied by the UI.

It also seems to be taking the first selected object in the list, rather than the object the drag started from, or the active object.