Bug 116646 – [Cairo] Fail to draw box-shadow if origin is very big and scale is not 1.

• Status: UNCONFIRMED
• Component: Layout and Rendering

[Yonggeol Jung]

When try to draw box-shadow to big origin and page scale factor is not 1, it fails to draw.

[Yonggeol Jung]

Created attachment 202636 [details]
testcase

After clicking "Scroll" button, you can see white circle with blue shadow-box.
But webkit-efl port doesn't display this.

[Yonggeol Jung]

Created attachment 202637 [details]
Patch

[Yonggeol Jung]

Created attachment 202638 [details]
Patch

[Chris Dumez]

Comment on attachment 202638 [details]
Patch

You probably need a test for it (or rebase existing test if already covered).

[Yonggeol Jung]

It's strange. 
I made some test case for this issue. 
When running test case using Minibrowser, 
it's not showing properly but result image file of layout-test shows fine.
Maybe the problem is related to repainting.
I'll check more.

[Martin Robinson]

Comment on attachment 202638 [details]
Patch

Can you show the stack trace of the failing call? It probably makes sense to workaround this issue in drawRectShadow, so that it doesn't need to be fixed in every place that calls the method.

[Yonggeol Jung]

Created attachment 203406 [details]
callstack

This is call stack for the test-case which I uploaded.
I  caught when "_cairo_matrix_to_pixman_matrix function" returns CAIRO_STATUS_INVALID_MATRIX.

// cairo-matrix.c 
static cairo_status_t_cairo_matrix_to_pixman_matrix ()
{
    ...
    if (_cairo_matrix_has_unity_scale (matrix))
        return CAIRO_STATUS_SUCCESS;

    if (unlikely (fabs (matrix->xx) > PIXMAN_MAX_INT ||
                  fabs (matrix->xy) > PIXMAN_MAX_INT ||
                  fabs (matrix->x0) > PIXMAN_MAX_INT ||
                  fabs (matrix->yx) > PIXMAN_MAX_INT ||
                  fabs (matrix->yy) > PIXMAN_MAX_INT ||
                  fabs (matrix->y0) > PIXMAN_MAX_INT))
    {
        return _cairo_error (CAIRO_STATUS_INVALID_MATRIX);   // => here
    }
   ....
}

[Brady Eidson]

Comment on attachment 202638 [details]
Patch

r- to clear stale patches from the review queue