[cairo] [PATCH] stroker: Check for scaling overflow in computing half line widths

[Miguel Gomez]

Resubmitting this to the list as I wasn't subscribed.

> > Would it be possible to a test that reproduces the issue?
> 
> Yes, Miguel has a code snippet to reproduce the crash, it could
> perfectly be a test.

Thanks for working on this guys!!

This is the test I'm using to reproduce the crash:

===============================================
#include <cairo.h>

int main()
{
    cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 64, 64);
    cairo_t* cr = cairo_create(surface);

    cairo_save(cr);
    cairo_matrix_t matrix;
    matrix.xx = 1.0;
    matrix.yx = 0;
    matrix.xy = 0;
    matrix.yy = 4294967295.0;
    matrix.x0 = 8.0;
    matrix.y0 = -49392123873.00;
    cairo_transform(cr, &matrix);

    cairo_rectangle(cr, 0.5, 0.5, 29.0, 22.0);
    cairo_set_line_width(cr, 1.0);
    cairo_stroke(cr);

    cairo_restore(cr);

    cairo_destroy(cr);
    cairo_surface_destroy(surface);
    
    return 0;
}
===============================================


-- 
Miguel Gomez
Igalia - www.igalia.com