render tree destruction speedup

[David Hyatt]

Taking advantage of the ability to test for document destruction by  
querying its renderer to avoid doing some extra work...

Index: khtml/rendering/render_block.cpp
===================================================================
RCS file:  
/local/home/cvs/Labyrinth/WebCore/khtml/rendering/render_block.cpp,v
retrieving revision 1.60
diff -u -p -r1.60 khtml/rendering/render_block.cpp
--- khtml/rendering/render_block.cpp	2003/10/01 20:58:55	1.60
+++ khtml/rendering/render_block.cpp	2003/10/02 01:42:38
@@ -319,7 +319,7 @@ void RenderBlock::removeChild(RenderObje
      RenderObject* prev = oldChild->previousSibling();
      RenderObject* next = oldChild->nextSibling();
      bool mergedBlocks = false;
-    if (!isInline() && !oldChild->isInline() &&  
!oldChild->continuation() &&
+    if (document()->renderer() && !isInline() && !oldChild->isInline()  
&& !oldChild->continuation() &&
          prev && prev->isAnonymous() && prev->childrenInline() &&
          next && next->isAnonymous() && next->childrenInline()) {
          // Take all the children out of the |next| block and put them  
in
Index: khtml/rendering/render_container.cpp
===================================================================
RCS file:  
/local/home/cvs/Labyrinth/WebCore/khtml/rendering/ 
render_container.cpp,v
retrieving revision 1.41
diff -u -p -r1.41 khtml/rendering/render_container.cpp
--- khtml/rendering/render_container.cpp	2003/10/01 20:58:55	1.41
+++ khtml/rendering/render_container.cpp	2003/10/02 01:42:38
@@ -158,32 +158,34 @@ RenderObject* RenderContainer::removeChi
      // So that we'll get the appropriate dirty bit set (either that a  
normal flow child got yanked or
      // that a positioned child got yanked).  We also repaint, so that  
the area exposed when the child
      // disappears gets repainted properly.
-    oldChild->setNeedsLayoutAndMinMaxRecalc();
+    if (document()->renderer()) {
+        oldChild->setNeedsLayoutAndMinMaxRecalc();
  #ifdef INCREMENTAL_REPAINTING
-    oldChild->repaint();
+        oldChild->repaint();
  #endif
+
+        // Keep our layer hierarchy updated.
+        oldChild->removeLayers(enclosingLayer());

-    // Keep our layer hierarchy updated.
-    oldChild->removeLayers(enclosingLayer());
-
-    // if oldChild is the start or end of the selection, then clear  
the selection to
-    // avoid problems of invalid pointers
-
-    // ### This is not the "proper" solution... ideally the selection  
should be maintained
-    // based on DOM Nodes and a Range, which gets adjusted  
appropriately when nodes are
-    // deleted/inserted near etc. But this at least prevents crashes  
caused when the start
-    // or end of the selection is deleted and then accessed when the  
user next selects
-    // something.
-
-    if (oldChild->isSelectionBorder()) {
-        RenderObject *root = oldChild;
-        while (root && root->parent())
-            root = root->parent();
-        if (root->isCanvas()) {
-            static_cast<RenderCanvas*>(root)->clearSelection();
+        // if oldChild is the start or end of the selection, then  
clear the selection to
+        // avoid problems of invalid pointers
+
+        // ### This is not the "proper" solution... ideally the  
selection should be maintained
+        // based on DOM Nodes and a Range, which gets adjusted  
appropriately when nodes are
+        // deleted/inserted near etc. But this at least prevents  
crashes caused when the start
+        // or end of the selection is deleted and then accessed when  
the user next selects
+        // something.
+
+        if (oldChild->isSelectionBorder()) {
+            RenderObject *root = oldChild;
+            while (root && root->parent())
+                root = root->parent();
+            if (root->isCanvas()) {
+                static_cast<RenderCanvas*>(root)->clearSelection();
+            }
          }
      }
-
+
      // remove the child
      if (oldChild->previousSibling())
           
oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());