[2537:2537:0517/170227.763409:INFO:CONSOLE:11] "=== POC start ===", source: http://127.0.0.1:19283/poc.html (11)
[STENCIL-POC] backend=Vulkan stencil=0x7502b48e3e40 rt=0x7522b48a4bd0 dims=512x512 loadOp=kClear renderArea=[20,20,236,236] initialContent=1 hasInitClear=0
[STENCIL-POC]   ** PARTIAL initial clear: only [20,20,236,236] of 512x512 cleared, but fHasPerformedInitialClear will latch TRUE for the WHOLE attachment **
[2537:2537:0517/170228.045622:INFO:CONSOLE:11] "Canvas A: T0 done (partial stencil clear, top-left quarter)", source: http://127.0.0.1:19283/poc.html (11)
[STENCIL-POC] backend=Vulkan stencil=0x7502b48e3e40 rt=0x7522b48aded0 dims=512x512 loadOp=kLoad renderArea=[276,276,492,492] initialContent=1 hasInitClear=1
[STENCIL-POC]   ******** BUG TRIGGERED ********
[STENCIL-POC]   stencilLoadOp=kLoad (fallthrough from kUserBitsCleared because hasPerformedInitialClear()==true) over renderArea=[276,276,492,492], but this stencil attachment was only ever LOAD_OP_CLEAR'd over [20,20,236,236]. The remainder is uninitialised VkImage memory (vkCreateImage initialLayout=UNDEFINED, never written). VK_ATTACHMENT_LOAD_OP_LOAD will read it; the Redbook cover pass (kNotEqual 0) exposes it to getImageData(). CWE-908.