Internet Explorer accessibility breaks when html page loads frame and frame is loaded with some latency more than one second.
When the frame is loaded quickly there is no problem, but with latency I get error for retrieving accessibility object.
A further investigation shows that there are some differences between UI Accessibility and MicroSoft Active Accessibility.
It works most of time with UIA and doesn't work with MSAA technology.
Steps to reproduce:
Start HTTP server with latency.
For instance limit speed to 0.1 KB/s
Simple HTTP server with this ability you can download here: http://www.rejetto.com/hfs/?f=dl
Put testmain.html and testframe.html in the same folder.
Start Microsoft Inspect tool from SDK: http://msdn.microsoft.com/en-us/library/windows/desktop/dd318521%28v=vs.85%29.aspx
Configure it to MSAA , Watch Cursor, Show Highlight Rectangle.
Open Internet Explorer
Navigate to testmain.html
Put the mouse cursor near the top left corner of the page.
You'll see the yellow rectangle changing while the pages are loading.
After the frame has been loaded it can be noticed that Inspect tool cannot get the object.
For instance that:
How found: Mouse move (85,157)
hwnd=0x0000000000010918 32bit class="Internet Explorer_Server" style=0x56000000 ex=0x0
------
Cannot get object from point:
[Error: FromPoint: hr=0xFFFFFFFF80004005 - Unspecified error]
Internet Explorer crashes sometimes as well while getting the accessibility object.
Dump analysis:
00000076`ce22af38 00007ff9`58f7b87b mshtml!CWindow::Doc
00000076`ce22af40 00007ff9`7a742053 mshtml!CAccWindow::accHitTest+0x6b
00000076`ce22afb0 00007ff9`7a853461 rpcrt4!Invoke+0x73
00000076`ce22b010 00007ff9`7a7596c0 rpcrt4!Ndr64StubWorker+0xfc9
00000076`ce22b710 00007ff9`7c70f073 rpcrt4!NdrStubCall3+0x10d
00000076`ce22ba30 00007ff9`7c7097bd combase!CStdStubBuffer_Invoke+0xbf [d:\9147\com\combase\ndr\ndrole\stub.cxx @ 1507]
00000076`ce22ba70 00007ff9`7c594f5a combase!SyncStubInvoke+0x21d [d:\9147\com\combase\dcomrem\channelb.cxx @ 1664]
00000076`ce22bc10 00007ff9`7c70c059 combase!CCtxComChnl::ContextInvoke+0x27a [d:\9147\com\combase\dcomrem\ctxchnl.cxx @ 1377]
00000076`ce22be20 00007ff9`7c708fb0 combase!AppInvoke+0x378 [d:\9147\com\combase\dcomrem\channelb.cxx @ 1469]
00000076`ce22bf10 00007ff9`7c70bf26 combase!ComInvokeWithLockAndIPID+0x676 [d:\9147\com\combase\dcomrem\channelb.cxx @ 2314]
00000076`ce22c150 00007ff9`7c5cd786 combase!ComInvoke+0x17a [d:\9147\com\combase\dcomrem\channelb.cxx @ 2030]
00000076`ce22c190 00007ff9`7c597fb0 combase!ThreadDispatch+0x20 [d:\9147\com\combase\dcomrem\chancont.cxx @ 364]
00000076`ce22c1c0 00007ff9`7ad2250d combase!ThreadWndProc+0xac [d:\9147\com\combase\dcomrem\chancont.cxx @ 713]
00000076`ce22c220 00007ff9`7ad22367 user32!UserCallWinProcCheckWow+0x149
00000076`ce22c2f0 00007ff9`6367dbed user32!DispatchMessageWorker+0x1a7
00000076`ce22c370 00007ff9`6361ed2b ieframe!CTabWindow::_TabWindowThreadProc+0x64c
00000076`ce22f5f0 00007ff9`71437e6f ieframe!LCIETab_ThreadProc+0x3a3
00000076`ce22f720 00007ff9`6287717f iertutil!_IsoThreadProc_WrapperToReleaseScope+0x1f
00000076`ce22f750 00007ff9`7ab213d2 IEShims!NS_CreateThread::DesktopIE_ThreadProc+0x9f
00000076`ce22f7a0 00007ff9`7cab03c4 kernel32!BaseThreadInitThunk+0x22
00000076`ce22f7d0 00000000`00000000 ntdll!RtlUserThreadStart+0x34
All files are located here:
https://mega.co.nz/#F!8w9i2CSD!3xB3ZY7b4maYshXzvWk_ZQ