ZDoom

I was unable to reproduce this, regular and double bind on the same key are properly recognized.

Same problem for me, with GZDoom v4.3.3, Windows 10, 64 bits, no mod.

If I bind like this :
unbind a
doublebind a "echo double"
...when i simple-press (or double-press) the A key, the message "double" is always displayed.

If I bind like that :
bind a "echo simple"
doublebind a "echo double"
...same result, when i simple-press (or double-press) the A key, the message "double" is always displayed. There is no way to trig the simplebind action.

It seems that doublebind is broken. It overrides normal bind, i.e. mouse2 is bound to +jump, I doublebind mouse2 to +use and now it executes +use whether I doubleclick the key or press once. I tried the latest stable build (4.1.2) and the latest dev build (g4.2pre-130-gb8a188705 on 2019-06-06 22:15:20), the problem preserves in both builds.