Lockup on Windows 10 using Office 2010 theme

I had posted this in a forum on Windows 10 experience ...

We are locking up on Windows 10 when the user maximizes the app and has an MDI window maximized. The user moves over the application close icon and the MDI icons below overlap that icon. CJ goes in to an infinite loop processing the non client hit test event. The code is in XTPFramehook.cpp in OnHookMessage. There the code checks the "point.y < GetCaptionHeight()" and returns true. This code just keeps getting executed until we kill the process using task manager.

I can easily duplicate this in 16.4 with the Codejock RibbonMDI sample. Build the sample with VS 2012 (unicode, 64 bit) and run it. Maximize the application. Then maximize the MDI document. Go to the "options" drop down on the right side of the frame and pick, e.g., Office2010 Aqua. Make sure frame transparency is on (it should be on by default). Notice you can barely see the document MDI icons, restore, close etc. with the Office2010 color themes. That is an issue we have filed a bug report on when a user has Aero turned on (which uses Windows DWM and that can't be turned off in WIn 8 or Win 10). Move over one of the icons. Notice the height extends into the frame's big red close "X" icon. This overlap is the key to the lockup. Now start moving the mouse around so it goes over the MDI and App close icons. The sample quickly locks up.

Debugging I found that this appears to be related to the "allow DWM" capabiltiy. In our app I have added this code to avoid the problem (and the impossible to see MDI  icon issue):

CXTPCommandBarsFrameHook::m_bAllowDwm = FALSE;

We have the beta for 17 and I'll be testing it shortly to see if the issue (and the impossible to see icon issue) is fixed there. But a fix for 16 is needed.

Now we see another issue with frame transparency turned off. If the user has the task bar at the left or top of the monitor and maximizes our app with the white theme, a thin translucent strip of white appears under the task bar. This isn't part of the app frame as the frame isn't clipped by the task bar. The appearance looks the same as if I move the app frame (unmaximized) just under the task bar a bit if it wasn't for the fact that doing so causes the frame to actually go under the bar (where you can see, e.g., the QAT and app button being clipped and hence part of the translucent merging that occurs).

It was Beta 1.