michael@0: From: Robert O'Callahan <robert@ocallahan.org>
michael@0: Bug 768348. Avoid ExtCreatePen failures by avoiding rounding widths and dash lengths down to zero. r=jrmuizel
michael@0: 
michael@0: diff --git a/gfx/cairo/cairo/src/cairo-win32-printing-surface.c b/gfx/cairo/cairo/src/cairo-win32-printing-surface.c
michael@0: --- a/gfx/cairo/cairo/src/cairo-win32-printing-surface.c
michael@0: +++ b/gfx/cairo/cairo/src/cairo-win32-printing-surface.c
michael@0: @@ -1251,22 +1251,24 @@ static cairo_int_status_t
michael@0:  {
michael@0:      cairo_win32_surface_t *surface = abstract_surface;
michael@0:      cairo_int_status_t status;
michael@0:      HPEN pen;
michael@0:      LOGBRUSH brush;
michael@0:      COLORREF color;
michael@0:      XFORM xform;
michael@0:      DWORD pen_style;
michael@0: +    DWORD pen_width;
michael@0:      DWORD *dash_array;
michael@0:      HGDIOBJ obj;
michael@0:      unsigned int i;
michael@0:      cairo_solid_pattern_t clear;
michael@0:      cairo_matrix_t mat;
michael@0:      double scale;
michael@0: +    double scaled_width;
michael@0:  
michael@0:      status = _cairo_surface_clipper_set_clip (&surface->clipper, clip);
michael@0:      if (status)
michael@0:  	return status;
michael@0:  
michael@0:      if (op == CAIRO_OPERATOR_CLEAR) {
michael@0:  	_cairo_win32_printing_surface_init_clear_color (surface, &clear);
michael@0:  	source = (cairo_pattern_t*) &clear;
michael@0: @@ -1288,17 +1290,21 @@ static cairo_int_status_t
michael@0:      _cairo_matrix_factor_out_scale (&mat, &scale);
michael@0:  
michael@0:      pen_style = PS_GEOMETRIC;
michael@0:      dash_array = NULL;
michael@0:      if (style->num_dashes) {
michael@0:  	pen_style |= PS_USERSTYLE;
michael@0:  	dash_array = calloc (sizeof (DWORD), style->num_dashes);
michael@0:  	for (i = 0; i < style->num_dashes; i++) {
michael@0: -	    dash_array[i] = (DWORD) (scale * style->dash[i]);
michael@0: +	    DWORD dashes = (DWORD) (scale * style->dash[i]);
michael@0: +	    /* zero dash-lengths cause ExtCreatePen to fail. Make the dashes
michael@0: +	     * longer if necessary.
michael@0: +	     */
michael@0: +	    dash_array[i] = MAX(1, dashes);
michael@0:  	}
michael@0:      } else {
michael@0:  	pen_style |= PS_SOLID;
michael@0:      }
michael@0:  
michael@0:      SetMiterLimit (surface->dc, (FLOAT) (style->miter_limit), NULL);
michael@0:      if (source->type == CAIRO_PATTERN_TYPE_SOLID) {
michael@0:  	cairo_solid_pattern_t *solid = (cairo_solid_pattern_t *) source;
michael@0: @@ -1310,18 +1316,29 @@ static cairo_int_status_t
michael@0:  	/* Color not used as the pen will only be used by WidenPath() */
michael@0:  	color = RGB (0,0,0);
michael@0:      }
michael@0:      brush.lbStyle = BS_SOLID;
michael@0:      brush.lbColor = color;
michael@0:      brush.lbHatch = 0;
michael@0:      pen_style |= _cairo_win32_line_cap (style->line_cap);
michael@0:      pen_style |= _cairo_win32_line_join (style->line_join);
michael@0: +    scaled_width = scale * style->line_width;
michael@0: +    if (scaled_width == 0.0)
michael@0: +        return status;
michael@0: +    pen_width = (DWORD)scaled_width;
michael@0: +    if (pen_width == 0) {
michael@0: +        /* ExtCreatePen will fail if passed zero width. We have to choose
michael@0: +         * between drawing something too wide, or drawing nothing at all.
michael@0: +         * Let's draw something.
michael@0: +         */
michael@0: +        pen_width = 1;
michael@0: +    }
michael@0:      pen = ExtCreatePen(pen_style,
michael@0: -		       scale * style->line_width,
michael@0: +		       pen_width,
michael@0:  		       &brush,
michael@0:  		       style->num_dashes,
michael@0:  		       dash_array);
michael@0:      if (pen == NULL)
michael@0:  	return _cairo_win32_print_gdi_error ("_win32_surface_stroke:ExtCreatePen");
michael@0:      obj = SelectObject (surface->dc, pen);
michael@0:      if (obj == NULL)
michael@0:  	return _cairo_win32_print_gdi_error ("_win32_surface_stroke:SelectObject");