Revert 157422 "Remove lots of code related synchronously attaching"

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 650af854a80758d418cecf057cc2897e2bc8857b..2bc7123aa6726290d5c648d1121d86e115467482 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -987,6 +987,9 @@ inline void Node::detachNode(Node* root, const AttachContext& context)
             continue;
         }
         // Handle normal reattaches from style recalc (ex. display type changes)
+        // or descendants of lazy attached nodes that got actually attached, for example,
+        // by innerHTML or editing.
+        // FIXME: innerHTML and editing should also lazyAttach.
         if (node->attached())
             node->detach(context);
         node = NodeTraversal::nextSkippingChildren(node, root);
@@ -995,6 +998,7 @@ inline void Node::detachNode(Node* root, const AttachContext& context)
 
 void Node::reattach(const AttachContext& context)
 {
+    ASSERT(document().inStyleRecalc());
     AttachContext reattachContext(context);
     reattachContext.performingReattach = true;
 
@@ -1004,10 +1008,30 @@ void Node::reattach(const AttachContext& context)
 
 void Node::attach(const AttachContext&)
 {
-    ASSERT(document().inStyleRecalc());
     ASSERT(!attached());
     ASSERT(!renderer() || (renderer()->style() && (renderer()->parent() || renderer()->isRenderView())));
 
+    // If this node got a renderer it may be the previousRenderer() of sibling text nodes and thus affect the
+    // result of Text::textRendererIsNeeded() for those nodes.
+    // FIXME: This loop is no longer required once we lazy attach all the time.
+    if (renderer() && !document().inStyleRecalc()) {
+        for (Node* next = nextSibling(); next; next = next->nextSibling()) {
+            if (next->renderer())
+                break;
+            if (!next->attached())
+                break; // Assume this means none of the following siblings are attached.
+            if (!next->isTextNode())
+                continue;
+            ASSERT(!next->renderer());
+            toText(next)->reattach();
+            // If we again decided not to create a renderer for next, we can bail out the loop,
+            // because it won't affect the result of Text::textRendererIsNeeded() for the rest
+            // of sibling nodes.
+            if (!next->renderer())
+                break;
+        }
+    }
+
     setAttached();
     clearNeedsStyleRecalc();