Context: Debian running in a Virtualbox VM on a Windows 10 host. Everything works fine, including all keyboard stuff (i.e., dead keys, German layout etc.).
When I press Alt-Tab, there appear the three letters
;3~ in my bash'es. They appear exactly in the instance when I "key-down" the Tab key.
This, fascinatingly, does not happen in other X windows (e.g., emacs), or when I start a vi inside said bash xterm. It does happen in other spaces where readline or similar command line editing is used (e.g., in a
irb ruby shell).
If I run
cat (without parameters) in the bash, then the following symbols appear:
When I press (and release) only the Alt or only the Tab key, nothing special happens (for Alt: nothing; for Tab: a regular tabulator is inserted properly).
xkbevd spits out the following:
# Alt-Down XkbStateNotify event, serial 13, synthetic no, device 3, time 237454199, keycode 64, eventType KeyPress, group= 0, base= 0, latched= 0, locked= 0, mods= 0x08*, base= 0x08*, latched= 0x00, locked= 0x00 grab mods= 0x08*, compat grab mods= 0x08* lookup mods= 0x08*, compat lookup mods= 0x08* compatState = 0x08*, ptr_buttons= 0x0000 # Tab-Down (now the Windows task switcher is displayed) ^[[29;3~ XkbStateNotify event, serial 13, synthetic no, device 3, time 237455504, keycode 64, eventType KeyRelease, group= 0, base= 0, latched= 0, locked= 0, mods= 0x00*, base= 0x00*, latched= 0x00, locked= 0x00 grab mods= 0x00*, compat grab mods= 0x00* lookup mods= 0x00*, compat lookup mods= 0x00* compatState = 0x00*, ptr_buttons= 0x0000 # Tab-Up (now the switch to whatever Windows window happens) # Alt-Up
On the Virtualbox side I checked the settings, and aside from capturing the keyboard / mouse (which I definitely do not wish to do) found no option which even sounded vaguely like being related. It also does not matter whether it is running in seamless, fullscreen or regular mode.
Do you know of some Linux-based setting? Maybe something related to the TERM stuff? Or rather in the X subsystem?