1 files changed, 40 insertions, 27 deletions

diff --git a/Source/WebCore/rendering/OrderIterator.cpp b/Source/WebCore/rendering/OrderIterator.cpp
index e09924f97..fade9388c 100644
--- a/Source/WebCore/rendering/OrderIterator.cpp
+++ b/Source/WebCore/rendering/OrderIterator.cpp
@@ -32,31 +32,16 @@
 #include "config.h"
 #include "OrderIterator.h"
 
-#include "RenderFlexibleBox.h"
-#include "RenderGrid.h"
+#include "RenderBox.h"
 
 namespace WebCore {
 
-static const int cInvalidIndex = -1;
-
 OrderIterator::OrderIterator(RenderBox& containerBox)
     : m_containerBox(containerBox)
 {
     reset();
 }
 
-void OrderIterator::setOrderValues(OrderValues&& orderValues)
-{
-    reset();
-    m_orderValues = std::move(orderValues);
-    if (m_orderValues.size() < 2)
-        return;
-
-    std::sort(m_orderValues.begin(), m_orderValues.end());
-    auto nextElement = std::unique(m_orderValues.begin(), m_orderValues.end());
-    m_orderValues.shrinkCapacity(nextElement - m_orderValues.begin());
-}
-
 RenderBox* OrderIterator::first()
 {
     reset();
@@ -65,25 +50,22 @@ RenderBox* OrderIterator::first()
 
 RenderBox* OrderIterator::next()
 {
-    int endIndex = m_orderValues.size();
     do {
         if (m_currentChild) {
             m_currentChild = m_currentChild->nextSiblingBox();
             continue;
         }
 
-        if (m_orderIndex == endIndex)
-            return nullptr;
-
-        if (m_orderIndex != cInvalidIndex) {
-            ++m_orderIndex;
-            if (m_orderIndex == endIndex)
-                return nullptr;
-        } else
+        if (m_orderIndex)
+            ++m_orderIndex.value();
+        else
             m_orderIndex = 0;
 
+        if (m_orderIndex.value() >= m_orderValues.size())
+            return nullptr;
+
         m_currentChild = m_containerBox.firstChildBox();
-    } while (!m_currentChild || m_currentChild->style().order() != m_orderValues[m_orderIndex]);
+    } while (!m_currentChild || m_currentChild->style().order() != m_orderValues[m_orderIndex.value()]);
 
     return m_currentChild;
 }
@@ -91,7 +73,38 @@ RenderBox* OrderIterator::next()
 void OrderIterator::reset()
 {
     m_currentChild = nullptr;
-    m_orderIndex = cInvalidIndex;
+    m_orderIndex = std::nullopt;
+}
+
+OrderIteratorPopulator::OrderIteratorPopulator(OrderIterator& iterator)
+    : m_iterator(iterator)
+{
+    // Note that we don't release the memory here, we only invalidate the size
+    // This avoids unneeded reallocation if the size ends up not changing.
+    m_iterator.m_orderValues.shrink(0);
 }
 
+OrderIteratorPopulator::~OrderIteratorPopulator()
+{
+    m_iterator.reset();
+
+    if (m_iterator.m_orderValues.size() > 1)
+        removeDuplicatedOrderValues();
+}
+
+void OrderIteratorPopulator::removeDuplicatedOrderValues()
+{
+    auto& orderValues = m_iterator.m_orderValues;
+
+    std::sort(orderValues.begin(), orderValues.end());
+    auto nextElement = std::unique(orderValues.begin(), orderValues.end());
+    orderValues.shrinkCapacity(nextElement - orderValues.begin());
+}
+
+void OrderIteratorPopulator::collectChild(const RenderBox& child)
+{
+    m_iterator.m_orderValues.append(child.style().order());
+}
+
+
 } // namespace WebCore