Update the first letter when the first line is changed by adding a new text at its start.

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 11 matching lines @@
  */
 
 #include "config.h"
 #include "core/rendering/RenderBlock.h"
 
 #include "HTMLNames.h"
 #include "core/accessibility/AXObjectCache.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/OverflowEvent.h"
+#include "core/dom/Text.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/page/Frame.h"
 #include "core/page/FrameView.h"
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/platform/graphics/FloatQuad.h"
 #include "core/platform/graphics/GraphicsContextStateSaver.h"
 #include "core/platform/graphics/transforms/TransformState.h"
@@ skipping 6675 matching lines @@
 }
 
 void RenderBlock::updateFirstLetter()
 {
     if (!document().styleSheetCollections()->usesFirstLetterRules())
         return;
     // Don't recur
     if (style()->styleType() == FIRST_LETTER)
         return;
 
-    // FIXME: We need to destroy the first-letter object if it is no longer the first child. Need to find
-    // an efficient way to check for that situation though before implementing anything.
     RenderObject* firstLetterBlock = findFirstLetterBlock(this);
     if (!firstLetterBlock)
         return;
 
     // Drill into inlines looking for our first text child.
     RenderObject* currChild = firstLetterBlock->firstChild();
     while (currChild) {
         if (currChild->isText())
             break;
         if (currChild->isListMarker())
@@ skipping 10 matching lines @@
             // We found a lower-level node with first-letter, which supersedes the higher-level style
             firstLetterBlock = currChild;
             currChild = currChild->firstChild();
         } else
             currChild = currChild->firstChild();
     }
 
     if (!currChild)
         return;
 
-    // If the child already has style, then it has already been created, so we just want
-    // to update it.
     if (currChild->parent()->style()->styleType() == FIRST_LETTER) {
+        // Destroy the first-letter object if it is no longer the first child.
+        RenderObject* remainingText = currChild->parent()->nextSibling();

[esprehn, 2013/09/09 21:22:57]

How do you know the currentCuild->parent() has a nextSibling and that it's not
wrapped in an anonymous thing?

[joone, 2013/09/09 22:36:25]

The currentChild is the firstLetter(RenderTextFragment) so its
parent(RenderInLine)'s next sibling should be the
remainingText(RenderTextFragment).The RenderInLine has the firstLetter object.
You can understand this from the createFirstLetterRenderer method. 

+        if (currChild->node() != remainingText->node()) {
+            LayoutStateDisabler layoutStateDisabler(view());
+
+            RenderObject* oldRemainingText = toRenderBoxModelObject(currChild->parent())->firstLetterRemainingText();
+            if (oldRemainingText)
+                toRenderText(oldRemainingText)->setText(toText(oldRemainingText->node())->data().impl());
+
+            createFirstLetterRenderer(firstLetterBlock, remainingText);

[esprehn, 2013/09/09 21:22:57]

What destroyed the original RenderTextFragment that was there?

[joone, 2013/09/09 22:36:25]

When setting a new text to RenderTextFragment(RemainingText), the firstLetter's
parent(RenderInLine) is destroyed. You can see the code in
RenderTextFragment::setText

+            return;
+        }
+
+        // If the child already has style, then it has already been created, so we just want
+        // to update it.
         updateFirstLetterStyle(firstLetterBlock, currChild);
         return;
     }
 
     if (!currChild->isText() || currChild->isBR())
         return;
 
     // Our layout state is not valid for the repaints we are going to trigger by
     // adding and removing children of firstLetterContainer.
     LayoutStateDisabler layoutStateDisabler(view());
@@ skipping 1262 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace WebCore