Hang after application switch

[hanche@…]

Using the 1.6.2-apple1 server on top of 2.4.0_rc1 and starting an xterm, I can type into the xterm as usual. After switching from X11 to another app and back, the xterm is now unresponsive. I can still open new xterms and other X applications, and their windows will show, but they are all unresponsive, both to keypresses and buttonpresses. Also, I cannot move any X window. I can still quit X11 in the usual way.

Perhaps interestingly, if I run xev from a Terminal window with X11 in the hung state, the xev window appears, and a number of events shows up in the terminal window, ending with a ConfigureNotify event. Then no more events are listed while I move the mouse over the xev window, click on it, etc. But once I quit X11, a flood of events appear in the terminal window, including MotionNotify, ButtonRelease, LeaveNotify, EnterNotify, ...

I attach a sample of X11.bin taken while I was typing furiously into an unresponsive xterm.

I do not see this problem either with 1.4.2-apple46 or 1.5.3-apple12 (the version that came with 2.4.0_rc1).

[hanche@…]

Sample of X11.bin

[irony42@…]

On my machine, this only occurs if I switch to X11.app by clicking on an X11 window. If I switch to X11.app by cmd-Tab or by clicking on it's Dock icon, everything works as normal.

This doesn't really seem to be a crash at all, but rather an issue in the way X11.app manages it's windows.

[irony42@…]

After a second look, this issue only occurs when switching to X11.app by clicking on the content area of a window. All other methods of switching — cmd-Tab, Dock icon, Expose, and clicking on a window's title bar — do not cause the freeze.

[jeremyhu@…]

​http://cgit.freedesktop.org/~jeremyhu/xserver/commit/?id=7897b6c2d41bccb72c19418674c3526ecce29515