2 files changed, 26 insertions, 11 deletions
diff --git a/components/canvas/canvas_data.rs b/components/canvas/canvas_data.rs
index 778851524ba..38d84f2d00c 100644
--- a/components/canvas/canvas_data.rs
+++ b/components/canvas/canvas_data.rs
@@ -446,11 +446,12 @@ impl<'a> CanvasData<'a> {
 
     pub fn draw_image(
         &mut self,
-        image_data: Vec<u8>,
+        image_data: &[u8],
         image_size: Size2D<f64>,
         dest_rect: Rect<f64>,
         source_rect: Rect<f64>,
         smoothing_enabled: bool,
+        premultiply: bool,
     ) {
         // We round up the floating pixel values to draw the pixels
         let source_rect = source_rect.ceil();
@@ -469,6 +470,7 @@ impl<'a> CanvasData<'a> {
                 source_rect.size,
                 dest_rect,
                 smoothing_enabled,
+                premultiply,
                 &draw_options,
             );
         };
@@ -1306,17 +1308,24 @@ pub struct CanvasPaintState<'a> {
 /// image_size: The size of the image to be written
 /// dest_rect: Area of the destination target where the pixels will be copied
 /// smoothing_enabled: It determines if smoothing is applied to the image result
+/// premultiply: Determines whenever the image data should be premultiplied or not
 fn write_image(
     draw_target: &mut dyn GenericDrawTarget,
-    image_data: Vec<u8>,
+    mut image_data: Vec<u8>,
     image_size: Size2D<f64>,
     dest_rect: Rect<f64>,
     smoothing_enabled: bool,
+    premultiply: bool,
     draw_options: &DrawOptions,
 ) {
     if image_data.is_empty() {
         return;
     }
+
+    if premultiply {
+        pixels::rgba8_premultiply_inplace(&mut image_data);
+    }
+
     let image_rect = Rect::new(Point2D::zero(), image_size);
 
     // From spec https://html.spec.whatwg.org/multipage/#dom-context-2d-drawimage
diff --git a/components/canvas/canvas_paint_thread.rs b/components/canvas/canvas_paint_thread.rs
index 7234aaed4ab..808714b14e8 100644
--- a/components/canvas/canvas_paint_thread.rs
+++ b/components/canvas/canvas_paint_thread.rs
@@ -175,22 +175,27 @@ impl<'a> CanvasPaintThread<'a> {
                 .canvas(canvas_id)
                 .is_point_in_path(x, y, fill_rule, chan),
             Canvas2dMsg::DrawImage(
-                imagedata,
+                ref image_data,
                 image_size,
                 dest_rect,
                 source_rect,
                 smoothing_enabled,
-            ) => {
-                let data = imagedata.map_or_else(
-                    || vec![0; image_size.width as usize * image_size.height as usize * 4],
-                    |bytes| bytes.into_vec(),
-                );
+            ) => self.canvas(canvas_id).draw_image(
+                &*image_data,
+                image_size,
+                dest_rect,
+                source_rect,
+                smoothing_enabled,
+                true,
+            ),
+            Canvas2dMsg::DrawEmptyImage(image_size, dest_rect, source_rect) => {
                 self.canvas(canvas_id).draw_image(
-                    data,
+                    &vec![0; image_size.area() as usize * 4],
                     image_size,
                     dest_rect,
                     source_rect,
-                    smoothing_enabled,
+                    false,
+                    false,
                 )
             },
             Canvas2dMsg::DrawImageInOther(
@@ -204,11 +209,12 @@ impl<'a> CanvasPaintThread<'a> {
                     .canvas(canvas_id)
                     .read_pixels(source_rect.to_u64(), image_size.to_u64());
                 self.canvas(other_canvas_id).draw_image(
-                    image_data.into(),
+                    &image_data,
                     source_rect.size,
                     dest_rect,
                     source_rect,
                     smoothing,
+                    false,
                 );
             },
             Canvas2dMsg::MoveTo(ref point) => self.canvas(canvas_id).move_to(point),