Prevent recursive call of Document::execCommand() to protect from attack code

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index 98e8af33e8ad90cf68acbd0ff955a0b0ce0bb379..30a20dfbc338dd4e0e79f672c7b5e0df419c9fdc 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -156,8 +156,13 @@ CompositeEditCommand::~CompositeEditCommand()
     ASSERT(isTopLevelCommand() || !m_composition);
 }
 
+static int applyNestingCounter;
+
 void CompositeEditCommand::apply()
 {
+    if (applyNestingCounter)
+        return;
+
     if (!endingSelection().isContentRichlyEditable()) {
         switch (editingAction()) {
         case EditActionTyping:
@@ -183,7 +188,9 @@ void CompositeEditCommand::apply()
     ASSERT(frame);
     {
         EventQueueScope scope;
+        ++applyNestingCounter;

[leviw_travelin_and_unemployed, 2013/11/13 21:16:18]

I like the idea... Can we make this RAII instead?

         doApply();
+        --applyNestingCounter;
     }
 
     // Only need to call appliedEditing for top-level commands,