[ue4] Crash when using multi-page atlases on Android using UE 4.22

[aresguo]

.182 21154-21154/? A/DEBUG: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: Build fingerprint: 'Xiaomi/chiron/chiron:9/PKQ1.190118.001/V11.0.2.0.PDECNXM:user/release-keys'
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: Revision: '0'
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: ABI: 'arm'
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: pid: 20605, tid: 20892, name: RenderThread 2 >>> com.YourCompany.SpineUE4 <<<
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x8
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: Cause: null pointer dereference
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: r0 00000000 r1 00000004 r2 c72f165a r3 00000000
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: r4 00000004 r5 00000000 r6 c72f16b8 r7 c44dcb01
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: r8 424118bf r9 007fffff r10 0bb38435 r11 c896d218
2019-11-20 10:57:18.182 21154-21154/? A/DEBUG: ip 00000001 sp c896c830 lr c896cc30 pc ceb2e940
2019-11-20 10:57:18.189 21108-21108/? D/PowerKeeperPackageManager: updateCurrentPackageLocked, userId = 0
2019-11-20 10:57:18.206 1586-2060/? W/MiuiGesturePointerEventListener: onActionDown end: mGestureStatus = 0
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: backtrace:
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #00 pc 05346940 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (_ZN24FSlateRHIRenderingPolicy12DrawElementsER24FRHICommandListImmediateR16FSlateBackBufferR12TRefCountPtrI13FRHITexture2DES7_RK6TArrayI17FSlateRenderBatch17FDefaultAllocatorERK21FSlateRenderingParams+8796)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #1 pc 0535efe0 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FSlateRHIRenderer::DrawWindow_RenderThread(FRHICommandListImmediate&, FViewportInfo&, FSlateWindowElementList&, FSlateDrawWindowCommandParams const&)+10564)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #2 pc 05393c74 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #3 pc 03813284 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FNamedTaskThread::ProcessTasksNamedThread(int, bool)+2876)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #4 pc 03811d98 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FNamedTaskThread::ProcessTasksUntilQuit(int)+108)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #5 pc 048ee28c /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (RenderingThreadMain(FEvent*)+436)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #6 pc 04938b78 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FRenderingThread::Run()+20)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #7 pc 03897644 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FRunnableThreadPThread::Run()+164)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #8 pc 0380d770 /data/app/com.YourCompany.SpineUE4-8pHcwWX6ECKyuoAmAfakNw==/lib/arm/libUE4.so (FRunnableThreadPThread::_ThreadProc(void*)+80)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #9 pc 000717f1 /system/lib/libc.so (__pthread_start(void*)+22)
2019-11-20 10:57:18.238 21154-21154/? A/DEBUG: #10 pc 0001dfd1 /system/lib/libc.so (__start_thread+24)

[badlogic]

Do you only see this on Android?

[aresguo]

hi, i have finded the problem. In the SSpineWidget::Flush function,
renderData.Brush = MakeShareable(new FSlateMaterialBrush(*Material, FVector2D(64, 64)));
this line appear problem. renderData.Brush Should Be Cached. like this
renderData.Brush = GetSlateMaterialBrush(Material) .

[badlogic]

Oh wow, that is actually a great find! It might also solve #1458. I'm investigating the effects of the proposed fix and will get back to you once it lands in the 3.8 and 3.9-beta branches. Thanks for helping out!

[badlogic]

@aresguo GetSlateMaterialBrush() doesn't exist. Could you be more specific?

[badlogic]

Can't reproduce. @aresguo happy to reopen if you could be more specific about your fix.