cairo: Mark filename parameter for PdfSurface nullable

Fixes bug 644158.

diff --git a/vapi/cairo.vapi b/vapi/cairo.vapi
index 0ebc50b342f0a19a0a58ad071bb0ed5ca1dcb207..bc2d8cdd7d06cbf5a010d01aee8c1ec3f441fd80 100644 (file)
--- a/vapi/cairo.vapi
+++ b/vapi/cairo.vapi
@@ -511,7 +511,7 @@ namespace Cairo {
        [CCode (cname = "cairo_surface_t", cheader_filename = "cairo-pdf.h")]
        public class PdfSurface : Surface {
                [CCode (cname = "cairo_pdf_surface_create")]
-               public PdfSurface (string filename, double width_in_points, double height_in_points);
+               public PdfSurface (string? filename, double width_in_points, double height_in_points);
                [CCode (cname = "cairo_pdf_surface_create_for_stream")]
                public PdfSurface.for_stream (WriteFunc write_func, double width_in_points, double height_in_points);
                public void set_size (double width_in_points, double height_in_points);