Bug 1780567 - Fix shared target allocation for tasks with Existing mo…

…de r=gfx-reviewers,jgilbert Differential Revision: https://phabricator.services.mozilla.com/D152474
dothq · Jul 21, 2022 · 246371e · 246371e
1 parent 71ff4e1
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diff --git a/gfx/tests/crashtests/1780567.html b/gfx/tests/crashtests/1780567.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <style>
+        * {
+            overflow-inline: hidden;
+            border-end-end-radius: 14mm ! important;
+            border-left-color: WindowFrame;
+            backdrop-filter: saturate(70%);
+        }
+
+        INPUT {
+            outline: medium invert auto;
+        }
+
+        H2 {
+            padding: 69% !important;
+        }
+    </style>
+</head>
+<body>
+<h2 dir='ltr'><dfn> <i> <input></i> </dfn></h2></body>
+</html>
+
diff --git a/gfx/tests/crashtests/crashtests.list b/gfx/tests/crashtests/crashtests.list
@@ -219,3 +219,5 @@ pref(layout.css.backdrop-filter.enabled,true) load 1771294.html
 pref(layout.css.backdrop-filter.enabled,true) load 1771293.html
 pref(layout.css.backdrop-filter.enabled,true) load 1771556.html
 pref(layout.css.backdrop-filter.enabled,true) load 1771561.html
+load 1780567.html
+
diff --git a/gfx/wr/webrender/src/render_task_graph.rs b/gfx/wr/webrender/src/render_task_graph.rs
@@ -399,8 +399,11 @@ impl RenderTaskGraphBuilder {
                         let mut location = None;
                         let kind = task.kind.target_kind();
 
+                        // If a task is used as part of an existing-chain then we can't
+                        // safely share it (nor would we want to).
                         let can_use_shared_surface =
-                            task.kind.can_use_shared_surface();
+                            task.kind.can_use_shared_surface() &&
+                            task.free_after != PassId::INVALID;
 
                         if can_use_shared_surface {
                             // If we can use a shared surface, step through the existing shared