graphic: 0.876
device: 0.794
ppc: 0.768
architecture: 0.536
x86: 0.534
user-level: 0.516
semantic: 0.492
performance: 0.444
permissions: 0.415
mistranslation: 0.400
vnc: 0.386
register: 0.382
PID: 0.346
socket: 0.318
kernel: 0.238
i386: 0.235
arm: 0.202
hypervisor: 0.199
risc-v: 0.197
debug: 0.171
boot: 0.165
assembly: 0.162
peripherals: 0.125
network: 0.115
files: 0.095
VMM: 0.056
TCG: 0.049
KVM: 0.031
virtual: 0.026

Fullscreen mode splits screen over monitor boundaries on dual-monitor system

I originally reported this for the Android SDK emulator, which is built on QEMU: http://code.google.com/p/android/issues/detail?id=14336

Can confirm that this bug is present in stock QEMU shipped with Ubuntu 10.10:
QEMU PC emulator version 0.12.5 (qemu-kvm-0.12.5), Copyright (c) 2003-2008 Fabrice Bellard

Steps to reproduce:
- get a Linux machine with multiple-monitor setup (tested using NVidia proprietary driver on Ubuntu 10.10 x86_64, with two monitors side-by-side in 'TwinView' configuration)
- launch qemu
- hit ctrl+alt+f to go into fullscreen mode

Expected behavior:
- emulator should take over one screen (either the first screen, largest screen, or screen the emulator is presently on)
- emulator's display should center or scale to fit within available area of the taken-over screen

Actual behavior:
- emulator takes over both screens
- emulator's display is split over the boundary between the two screens

I have the exactly the same problem/behavior. You are not allone!

QEMU 0.12 is completely outdated nowadays ... can you still reproduce this issue with the latest version of QEMU (currently v2.8)? If yes, which graphical backend are you using? SDL1? SDL2? GTK?

[Expired for QEMU because there has been no activity for 60 days.]