From d120c10d494d312f7598732962319da065285fbc Mon Sep 17 00:00:00 2001
From: Alan Jeffrey <ajeffrey@mozilla.com>
Date: Tue, 13 Jun 2017 07:38:12 -0700
Subject: [PATCH] servo: Merge #17278 - Clear webrender image id when resizing
 a canvas (from asajeffrey:canvas-clear-webrender-image-key-when-resizing);
 r=emilio

<!-- Please describe your changes on the following line: -->

Webrender isn't very happy if images change size, so clear the webrender image key when resizing a canvas.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #17277
- [X] There are tests for these changes

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

Source-Repo: https://github.com/servo/servo
Source-Revision: 8c2a7d6787ba6cc1be699643e7a99021f08fe56b

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 5e42dde44ba721287fd88b3f3d0f6984d4904b0a
---
 servo/components/canvas/canvas_paint_thread.rs | 4 ++++
 servo/components/canvas/webgl_paint_thread.rs  | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/servo/components/canvas/canvas_paint_thread.rs b/servo/components/canvas/canvas_paint_thread.rs
index 39c633e127ba..b6360c638f9e 100644
--- a/servo/components/canvas/canvas_paint_thread.rs
+++ b/servo/components/canvas/canvas_paint_thread.rs
@@ -547,6 +547,10 @@ impl<'a> CanvasPaintThread<'a> {
 
     fn recreate(&mut self, size: Size2D<i32>) {
         self.drawtarget = CanvasPaintThread::create(size);
+        // Webrender doesn't let images change size, so we clear the webrender image key.
+        if let Some(image_key) = self.image_key.take() {
+            self.webrender_api.delete_image(image_key);
+        }
     }
 
     fn send_pixels(&mut self, chan: IpcSender<Option<Vec<u8>>>) {
diff --git a/servo/components/canvas/webgl_paint_thread.rs b/servo/components/canvas/webgl_paint_thread.rs
index 9f87d3a4f510..feabaed7d2aa 100644
--- a/servo/components/canvas/webgl_paint_thread.rs
+++ b/servo/components/canvas/webgl_paint_thread.rs
@@ -291,7 +291,7 @@ impl WebGLPaintThread {
     #[allow(unsafe_code)]
     fn recreate(&mut self, size: Size2D<i32>) -> Result<(), &'static str> {
         match self.data {
-            WebGLPaintTaskData::Readback(ref mut context, _, _) => {
+            WebGLPaintTaskData::Readback(ref mut context, ref webrender_api, ref mut image_key) => {
                 if size.width > self.size.width ||
                    size.height > self.size.height {
                     self.size = try!(context.resize(size));
@@ -299,6 +299,10 @@ impl WebGLPaintThread {
                     self.size = size;
                     context.gl().scissor(0, 0, size.width, size.height);
                 }
+                // Webrender doesn't let images change size, so we clear the webrender image key.
+                if let Some(image_key) = image_key.take() {
+                    webrender_api.delete_image(image_key);
+                }
             }
             WebGLPaintTaskData::WebRender(ref api, id) => {
                 let device_size = webrender_traits::DeviceIntSize::from_untyped(&size);