Fix #6799: set stacking_context_position correctly on

fragment_border_iterator

components/layout/block.rs

@@ -31,7 +31,7 @@ use app_units::{Au, MAX_AU};
 use context::LayoutContext;
 use display_list_builder::{BorderPaintingMode, DisplayListBuildState};
 use display_list_builder::BlockFlowDisplayListBuilding;
-use euclid::{Point2D, Size2D};
+use euclid::{Point2D, Size2D, Rect};
 use floats::{ClearType, FloatKind, Floats, PlacementInfo};
 use flow::{self, BaseFlow, EarlyAbsolutePositionInfo, Flow, FlowClass, ForceNonfloatedFlag};
 use flow::{BLOCK_POSITION_IS_STATIC, CLEARS_LEFT, CLEARS_RIGHT};
@@ -647,6 +647,14 @@ impl BlockFlow {
         &mut self.fragment
     }
 
+    pub fn stacking_relative_position(&self, coor: CoordinateSystem) -> Rect<Au> {
+        return self.fragment.stacking_relative_border_box(
+            &self.base.stacking_relative_position,
+            &self.base.early_absolute_position_info.relative_containing_block_size,
+            self.base.early_absolute_position_info.relative_containing_block_mode,
+            coor);
+    }
+
     /// Return the size of the containing block for the given immediate absolute descendant of this
     /// flow.
     ///

components/layout/display_list_builder.rs

@@ -2221,13 +2221,7 @@ impl BlockFlowDisplayListBuilding for BlockFlow {
         if state.clip_stack.is_empty() {
             return;
         }
-
-        let border_box = self.fragment.stacking_relative_border_box(
-            &self.base.stacking_relative_position,
-            &self.base.early_absolute_position_info.relative_containing_block_size,
-            self.base.early_absolute_position_info.relative_containing_block_mode,
-            CoordinateSystem::Parent);
-
+        let border_box = self.stacking_relative_position(CoordinateSystem::Parent);
         let transform = match self.fragment.transform_matrix(&border_box) {
             Some(transform) => transform,
             None => return,

components/layout/sequential.rs

@@ -12,7 +12,7 @@ use floats::SpeculatedFloatPlacement;
 use flow::{self, Flow, ImmutableFlowUtils, InorderFlowTraversal, MutableFlowUtils};
 use flow::{PostorderFlowTraversal, PreorderFlowTraversal};
 use flow::IS_ABSOLUTELY_POSITIONED;
-use fragment::FragmentBorderBoxIterator;
+use fragment::{FragmentBorderBoxIterator, CoordinateSystem};
 use generated_content::ResolveGeneratedContent;
 use incremental::RelayoutMode;
 use servo_config::opts;
@@ -105,15 +105,22 @@ pub fn iterate_through_flow_tree_fragment_border_boxes(root: &mut Flow, iterator
         flow.iterate_through_fragment_border_boxes(iterator, level, stacking_context_position);
 
         for kid in flow::mut_base(flow).child_iter_mut() {
-            let stacking_context_position = if kid.is_block_flow() &&
-                                               kid.as_block().fragment.establishes_stacking_context() {
-                let margin = Point2D::new(kid.as_block().fragment.margin.inline_start, Au(0));
-                *stacking_context_position + flow::base(kid).stacking_relative_position + margin
-            } else {
-                *stacking_context_position
-            };
-
-            // FIXME(#2795): Get the real container size.
+            let mut stacking_context_position = *stacking_context_position;
+            if kid.is_block_flow() && kid.as_block().fragment.establishes_stacking_context() {
+                stacking_context_position = Point2D::new(kid.as_block().fragment.margin.inline_start, Au(0)) +
+                                            flow::base(kid).stacking_relative_position +
+                                            stacking_context_position;
+                let relative_position = kid.as_block()
+                    .stacking_relative_position(CoordinateSystem::Own);
+                if let Some(matrix) = kid.as_block()
+                       .fragment
+                       .transform_matrix(&relative_position) {
+                    let transform_matrix = matrix.transform_point(&Point2D::zero());
+                    stacking_context_position = stacking_context_position +
+                                                Point2D::new(Au::from_f32_px(transform_matrix.x),
+                                                             Au::from_f32_px(transform_matrix.y))
+                }
+            }
             doit(kid, level + 1, iterator, &stacking_context_position);
         }
     }

tests/wpt/metadata/MANIFEST.json

@@ -321172,6 +321172,12 @@
      {}
     ]
    ],
+   "cssom/GetBoundingRect.html": [
+    [
+     "/cssom/GetBoundingRect.html",
+     {}
+    ]
+   ],
    "cssom/MediaList.html": [
     [
      "/cssom/MediaList.html",
@@ -553765,6 +553771,10 @@
    "f0d47464da9d30e70733f09af78f3e9f982c4406",
    "testharness"
   ],
+  "cssom/GetBoundingRect.html": [
+   "7e5a8b25753ac970c2d192376c9dd93943b3dbb5",
+   "testharness"
+  ],
   "cssom/MediaList.html": [
    "21d9e43514fb3a7fbf8933429242dc544224ef24",
    "testharness"

tests/wpt/web-platform-tests/cssom/GetBoundingRect.html

@@ -0,0 +1,30 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>getBoundingClientRect</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+
+    <style>
+      #foo {
+        margin: 0px 0px 0px 5px;
+        transform: translate(10px, 200px);
+        position: fixed;
+        left: 5px;
+        background-color: red;
+      }
+    </style>
+  </head>
+  <body>
+    <div id="foo">
+      FOO
+    </div>
+    <script>
+        test(function () {
+            var foo = document.getElementById("foo").getBoundingClientRect();
+            assert_equals(foo.left, 20);
+        });
+    </script>
+  </body>
+</html>