diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h
index 59dc344..bc022e3 100644
--- a/include/llvm/Analysis/CallGraph.h
+++ b/include/llvm/Analysis/CallGraph.h
@@ -77,7 +77,7 @@
 public:
   static char ID; // Class identification, replacement for typeinfo
   //===---------------------------------------------------------------------
-  // Accessors...
+  // Accessors.
   //
   typedef FunctionMapTy::iterator iterator;
   typedef FunctionMapTy::const_iterator const_iterator;
@@ -136,7 +136,7 @@
   CallGraphNode *getOrInsertFunction(const Function *F);
 
   //===---------------------------------------------------------------------
-  // Pass infrastructure interface glue code...
+  // Pass infrastructure interface glue code.
   //
 protected:
   CallGraph() {}
@@ -163,19 +163,31 @@
   Function *F;
   typedef std::pair<CallSite,CallGraphNode*> CallRecord;
   std::vector<CallRecord> CalledFunctions;
+  
+  /// NumReferences - This is the number of times that this CallGraphNode occurs
+  /// in the CalledFunctions array of this or other CallGraphNodes.
+  unsigned NumReferences;
 
-  CallGraphNode(const CallGraphNode &);           // Do not implement
+  CallGraphNode(const CallGraphNode &);            // DO NOT IMPLEMENT
+  void operator=(const CallGraphNode &);           // DO NOT IMPLEMENT
+  
+  void DropRef() { --NumReferences; }
+  void AddRef() { ++NumReferences; }
 public:
   typedef std::vector<CallRecord> CalledFunctionsVector;
 
+  
+  // CallGraphNode ctor - Create a node for the specified function.
+  inline CallGraphNode(Function *f) : F(f), NumReferences(0) {}
+  
   //===---------------------------------------------------------------------
-  // Accessor methods...
+  // Accessor methods.
   //
 
   typedef std::vector<CallRecord>::iterator iterator;
   typedef std::vector<CallRecord>::const_iterator const_iterator;
 
-  // getFunction - Return the function that this call graph node represents...
+  // getFunction - Return the function that this call graph node represents.
   Function *getFunction() const { return F; }
 
   inline iterator begin() { return CalledFunctions.begin(); }
@@ -185,9 +197,14 @@
   inline bool empty() const { return CalledFunctions.empty(); }
   inline unsigned size() const { return (unsigned)CalledFunctions.size(); }
 
-  // Subscripting operator - Return the i'th called function...
+  /// getNumReferences - Return the number of other CallGraphNodes in this
+  /// CallGraph that reference this node in their callee list.
+  unsigned getNumReferences() const { return NumReferences; }
+  
+  // Subscripting operator - Return the i'th called function.
   //
   CallGraphNode *operator[](unsigned i) const {
+    assert(i < CalledFunctions.size() && "Invalid index");
     return CalledFunctions[i].second;
   }
 
@@ -204,7 +221,10 @@
   /// removeAllCalledFunctions - As the name implies, this removes all edges
   /// from this CallGraphNode to any functions it calls.
   void removeAllCalledFunctions() {
-    CalledFunctions.clear();
+    while (!CalledFunctions.empty()) {
+      CalledFunctions.back().second->DropRef();
+      CalledFunctions.pop_back();
+    }
   }
   
   /// stealCalledFunctionsFrom - Move all the callee information from N to this
@@ -220,6 +240,7 @@
   /// one.
   void addCalledFunction(CallSite CS, CallGraphNode *M) {
     CalledFunctions.push_back(std::make_pair(CS, M));
+    M->AddRef();
   }
 
   /// removeCallEdgeFor - This method removes the edge in the node for the
@@ -240,11 +261,6 @@
   /// New CallSite instead.  Note that this method takes linear time, so it
   /// should be used sparingly.
   void replaceCallSite(CallSite Old, CallSite New, CallGraphNode *NewCallee);
-
-  friend class CallGraph;
-
-  // CallGraphNode ctor - Create a node for the specified function.
-  inline CallGraphNode(Function *f) : F(f) {}
 };
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Analysis/IPA/CallGraph.cpp b/lib/Analysis/IPA/CallGraph.cpp
index 152add9..9711013 100644
--- a/lib/Analysis/IPA/CallGraph.cpp
+++ b/lib/Analysis/IPA/CallGraph.cpp
@@ -53,7 +53,7 @@
     CallsExternalNode = new CallGraphNode(0);
     Root = 0;
   
-    // Add every function to the call graph...
+    // Add every function to the call graph.
     for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
       addToCallGraph(I);
   
@@ -169,12 +169,12 @@
 }
 
 void CallGraph::destroy() {
-  if (!FunctionMap.empty()) {
-    for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
-        I != E; ++I)
-      delete I->second;
-    FunctionMap.clear();
-  }
+  if (FunctionMap.empty()) return;
+  
+  for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+      I != E; ++I)
+    delete I->second;
+  FunctionMap.clear();
 }
 
 void CallGraph::print(raw_ostream &OS, Module*) const {
@@ -219,10 +219,11 @@
 
 void CallGraphNode::print(raw_ostream &OS) const {
   if (Function *F = getFunction())
-    OS << "Call graph node for function: '" << F->getName()
-       << "'<<0x" << this << ">>\n";
+    OS << "Call graph node for function: '" << F->getName() << "'";
   else
-    OS << "Call graph node <<null function: 0x" << this << ">>:\n";
+    OS << "Call graph node <<null function>>";
+  
+  OS << "<<0x" << this << ">>  #uses=" << getNumReferences() << '\n';
 
   for (const_iterator I = begin(), E = end(); I != E; ++I)
     if (Function *FI = I->second->getFunction())
@@ -241,7 +242,9 @@
   for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
     assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
     if (I->first == CS) {
-      CalledFunctions.erase(I);
+      I->second->DropRef();
+      *I = CalledFunctions.back();
+      CalledFunctions.pop_back();
       return;
     }
   }
@@ -254,6 +257,7 @@
 void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
   for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
     if (CalledFunctions[i].second == Callee) {
+      Callee->DropRef();
       CalledFunctions[i] = CalledFunctions.back();
       CalledFunctions.pop_back();
       --i; --e;
@@ -266,8 +270,10 @@
   for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
     assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
     CallRecord &CR = *I;
-    if (CR.second == Callee && !CR.first.getInstruction()) {
-      CalledFunctions.erase(I);
+    if (CR.second == Callee && CR.first.getInstruction() == 0) {
+      Callee->DropRef();
+      *I = CalledFunctions.back();
+      CalledFunctions.pop_back();
       return;
     }
   }
@@ -285,8 +291,11 @@
       
       // If the callee is changing, not just the callsite, then update it as
       // well.
-      if (NewCallee)
+      if (NewCallee) {
+        I->second->DropRef();
         I->second = NewCallee;
+        I->second->AddRef();
+      }
       return;
     }
   }
diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index d5967fb..9b8e0a1 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -293,10 +293,12 @@
       
       // If we inlined the last possible call site to the function, delete the
       // function body now.
-      if (Callee->use_empty() && 
-          (Callee->hasLocalLinkage() ||
-           Callee->hasAvailableExternallyLinkage()) &&
-          !SCCFunctions.count(Callee)) {
+      if (Callee->use_empty() && Callee->hasLocalLinkage() &&
+          !SCCFunctions.count(Callee) &&
+          // The function may be apparently dead, but if there are indirect
+          // callgraph references to the node, we cannot delete it yet, this
+          // could invalidate the CGSCC iterator.
+          CG[Callee]->getNumReferences() == 0) {
         DEBUG(errs() << "    -> Deleting dead function: "
               << Callee->getName() << "\n");
         CallGraphNode *CalleeNode = CG[Callee];
@@ -353,7 +355,7 @@
   // from the program.  Insert the dead ones in the FunctionsToRemove set.
   for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
     CallGraphNode *CGN = I->second;
-    if (CGN == 0 || CGN->getFunction() == 0)
+    if (CGN->getFunction() == 0)
       continue;
     
     Function *F = CGN->getFunction();
@@ -364,7 +366,8 @@
 
     if (DNR && DNR->count(F))
       continue;
-    if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage())
+    if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage() &&
+        !F->hasAvailableExternallyLinkage())
       continue;
     if (!F->use_empty())
       continue;
diff --git a/test/Transforms/Inline/indirect_resolve.ll b/test/Transforms/Inline/indirect_resolve.ll
new file mode 100644
index 0000000..4be55d4
--- /dev/null
+++ b/test/Transforms/Inline/indirect_resolve.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis
+; PR4834
+
+define i32 @main() {
+  %funcall1_ = call fastcc i32 ()* ()* @f1()
+  %executecommandptr1_ = call i32 %funcall1_()
+  ret i32 %executecommandptr1_
+}
+
+define internal fastcc i32 ()* @f1() nounwind readnone {
+  ret i32 ()* @f2
+}
+
+define internal i32 @f2() nounwind readnone {
+  ret i32 1
+}