Do the following:

• Open an email
• Type :help foo
• Press q

This happens:

panic: runtime error: index out of range

goroutine 1 [running]:
git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).focus(0xc000190200, 0x0, 0x0)
        /tmp/makepkg/aerc-git/src/aerc/widgets/aerc.go:298 +0x18f
git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).BeginExCommand.func1(0xc00053e018, 0x5)
        /tmp/makepkg/aerc-git/src/aerc/widgets/aerc.go:320 +0x9d
git.sr.ht/~sircmpwn/aerc/widgets.(*ExLine).Event(0xc0000917a0, 0x55e0c2df16e0, 0xc0000c81e0, 0xc0000c81e0)
        /tmp/makepkg/aerc-git/src/aerc/widgets/exline.go:51 +0x348
git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).Event(0xc000190200, 0x55e0c2df16e0, 0xc0000c81e0, 0x55e0c2d4bc01)
        /tmp/makepkg/aerc-git/src/aerc/widgets/aerc.go:148 +0x490
git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).simulate(0xc000190200, 0xc0001aec40, 0x7, 0x8)
        /tmp/makepkg/aerc-git/src/aerc/widgets/aerc.go:141 +0x9d
git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).Event(0xc000190200, 0x55e0c2df16e0, 0xc0000c8080, 0xc000187400)
        /tmp/makepkg/aerc-git/src/aerc/widgets/aerc.go:164 +0x39b
git.sr.ht/~sircmpwn/aerc/lib/ui.(*UI).Tick(0xc00009c460, 0xc000021700)
        /tmp/makepkg/aerc-git/src/aerc/lib/ui/ui.go:89 +0xcb
main.main()
        /tmp/makepkg/aerc-git/src/aerc/aerc.go:172 +0x550