Home » U++ Library support » Draw, Display, Images, Bitmaps, Icons » BufferPainter Clip Crash - Fatal error: Invalid memory access!
| BufferPainter Clip Crash - Fatal error: Invalid memory access! [message #59548] |
Wed, 25 January 2023 17:02  |
devilsclaw
Messages: 15
Registered: August 2022
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Promising Member |
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So I found a combination of actions that will cause clipping to return a invalid pointer in RenderPath of BufferPainter.
1) Use Clip and Draw out side of the clip region
2) Attach the object to follow the mouse
3) Repeatedly move the mouse in and out of the window frame at the bottom in random locations up to 30 seconds.
Attached is an example app in code of how to cause it.
Below is the offending code and the output of it getting a corrupted pointer
Y2 is the pointer getting corrupted. Also I am on linux
if(clip.GetCount()) {
printf("DC: Y1 = %i\n", y);
const ClippingLine& s = clip.Top()[y];
printf("DC: Y2 = %p\n", &s);
if(s.IsEmpty()) {
goto empty;
}
printf("DC: Y3 = %i\n", y);
if(!s.IsFull()) {
mf.Set(rg, s);
rf = &mf;
}
}
Results:
DC: Y1 = 525
DC: Y2 = 0x7f82b80571e8
DC: Y1 = 526
DC: Y2 = 0x7f82b80571f0
DC: Y3 = 526
DC: Y1 = 525
DC: Y2 = 0x7f82b80571e8
DC: Y1 = 526
DC: Y2 = 0x7f82b80571f0
DC: Y3 = 526
DC: MouseMove: x 16620 : y 16906 : 00000000
DC: Y1 = 526
DC: Y2 = 0x1070
[Updated on: Wed, 25 January 2023 17:02] Report message to a moderator |
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