gfx/cairo/premultiply-alpha-solid-gradients.patch

   1 Fix single and multi-stop solid gradients by multiplying by the alpha component. r=roc
   2
   3 This cairo commit that caused the problem: 2d790daa957471670f4ae0d3b22da89e4ee7111f.
   4 It was merged into mozilla-central with 1effb72d30cf
   5
   6 diff --git a/gfx/cairo/cairo/src/cairo-pattern.c b/gfx/cairo/cairo/src/cairo-pattern.c
   7 --- a/gfx/cairo/cairo/src/cairo-pattern.c
   8 +++ b/gfx/cairo/cairo/src/cairo-pattern.c
   9 @@ -2262,8 +2262,17 @@ _cairo_pattern_acquire_surface (const ca
  10
  11             if (src->n_stops)
  12             {
  13 +               cairo_color_t color;
  14 +
  15 +               /* multiply by alpha */
  16 +               _cairo_color_init_rgba (&color,
  17 +                       src->stops->color.red,
  18 +                       src->stops->color.green,
  19 +                       src->stops->color.blue,
  20 +                       src->stops->color.alpha);
  21 +
  22                 _cairo_pattern_init_solid (&solid,
  23 -                                          &src->stops->color,
  24 +                                          &color,
  25                                            CAIRO_CONTENT_COLOR_ALPHA);
  26             }
  27             else
  28 @@ -2295,9 +2304,17 @@ _cairo_pattern_acquire_surface (const ca
  29             }
  30             if (i == src->n_stops) {
  31                 cairo_solid_pattern_t solid;
  32 +               cairo_color_t color;
  33 +
  34 +               /* multiply by alpha */
  35 +               _cairo_color_init_rgba (&color,
  36 +                       src->stops->color.red,
  37 +                       src->stops->color.green,
  38 +                       src->stops->color.blue,
  39 +                       src->stops->color.alpha);
  40
  41                 _cairo_pattern_init_solid (&solid,
  42 -                                          &src->stops->color,
  43 +                                          &color,
  44                                            CAIRO_CONTENT_COLOR_ALPHA);
  45
  46                 status =