diff --git a/lib/Analysis/ArrayBoundChecker.cpp b/lib/Analysis/ArrayBoundChecker.cpp
index 549a22b..3d8b3b3 100644
--- a/lib/Analysis/ArrayBoundChecker.cpp
+++ b/lib/Analysis/ArrayBoundChecker.cpp
@@ -62,8 +62,7 @@
   const GRState *StInBound = state->AssumeInBound(Idx, NumElements, true);
   const GRState *StOutBound = state->AssumeInBound(Idx, NumElements, false);
   if (StOutBound && !StInBound) {
-    ExplodedNode *N = C.GenerateNode(S, StOutBound, true);
-
+    ExplodedNode *N = C.GenerateSink(StOutBound);
     if (!N)
       return;
   
@@ -80,7 +79,6 @@
       new RangedBugReport(*BT, BT->getDescription(), N);
 
     report->addRange(S->getSourceRange());
-
     C.EmitReport(report);
   }
 }
diff --git a/lib/Analysis/AttrNonNullChecker.cpp b/lib/Analysis/AttrNonNullChecker.cpp
index 01e1a1f..8668c75 100644
--- a/lib/Analysis/AttrNonNullChecker.cpp
+++ b/lib/Analysis/AttrNonNullChecker.cpp
@@ -39,7 +39,6 @@
 void AttrNonNullChecker::PreVisitCallExpr(CheckerContext &C, 
                                           const CallExpr *CE) {
   const GRState *state = C.getState();
-  const GRState *originalState = state;
 
   // Check if the callee has a 'nonnull' attribute.
   SVal X = state->getSVal(CE->getCallee());
@@ -74,7 +73,7 @@
     if (stateNull && !stateNotNull) {
       // Generate an error node.  Check for a null node in case
       // we cache out.
-      if (ExplodedNode *errorNode = C.GenerateNode(CE, stateNull, true)) {
+      if (ExplodedNode *errorNode = C.GenerateSink(stateNull)) {
 
         // Lazily allocate the BugType object if it hasn't already been
         // created. Ownership is transferred to the BugReporter object once
@@ -109,6 +108,5 @@
 
   // If we reach here all of the arguments passed the nonnull check.
   // If 'state' has been updated generated a new node.
-  if (state != originalState)
-    C.addTransition(C.GenerateNode(CE, state));
+  C.addTransition(state);
 }
diff --git a/lib/Analysis/BasicObjCFoundationChecks.cpp b/lib/Analysis/BasicObjCFoundationChecks.cpp
index 5a88a7a..424a0b3 100644
--- a/lib/Analysis/BasicObjCFoundationChecks.cpp
+++ b/lib/Analysis/BasicObjCFoundationChecks.cpp
@@ -563,12 +563,11 @@
     BT = new APIMisuse("message incorrectly sent to class instead of class "
                        "instance");
   
-  ExplodedNode *N = C.GenerateNode(ME, C.getState(), false);
+  ExplodedNode *N = C.GenerateNode();
+
   if (!N)
     return;
   
-  C.addTransition(N);
-  
   llvm::SmallString<200> buf;
   llvm::raw_svector_ostream os(buf);
 
diff --git a/lib/Analysis/CastToStructChecker.cpp b/lib/Analysis/CastToStructChecker.cpp
index ccd4a33..7c6fc7e 100644
--- a/lib/Analysis/CastToStructChecker.cpp
+++ b/lib/Analysis/CastToStructChecker.cpp
@@ -59,7 +59,7 @@
 
   // Now the cast-to-type is struct pointer, the original type is not void*.
   if (!OrigPointeeTy->isRecordType()) {
-    if (ExplodedNode *N = C.GenerateNode(CE)) {
+    if (ExplodedNode *N = C.GenerateNode()) {
       if (!BT)
         BT = new BuiltinBug("Cast from non-struct type to struct type",
                             "Casting a non-structure type to a structure type "
diff --git a/lib/Analysis/Checker.cpp b/lib/Analysis/Checker.cpp
index 985b1e0..0d907e5 100644
--- a/lib/Analysis/Checker.cpp
+++ b/lib/Analysis/Checker.cpp
@@ -16,3 +16,20 @@
 using namespace clang;
 
 Checker::~Checker() {}
+
+CheckerContext::~CheckerContext() {
+  // Do we need to autotransition?  'Dst' can get populated in a variety of
+  // ways, including 'addTransition()' adding the predecessor node to Dst
+  // without actually generated a new node.  We also shouldn't autotransition
+  // if we are building sinks or we generated a node and decided to not
+  // add it as a transition.
+  if (Dst.size() == size && !B.BuildSinks && !B.HasGeneratedNode) {
+    if (state && state != B.GetState(Pred)) {
+      static int autoTransitionTag = 0;
+      B.Tag = &autoTransitionTag;
+      addTransition(state);
+    }
+    else
+      Dst.Add(Pred);
+  }
+}
diff --git a/lib/Analysis/DereferenceChecker.cpp b/lib/Analysis/DereferenceChecker.cpp
index a8f5af3..4c4091c 100644
--- a/lib/Analysis/DereferenceChecker.cpp
+++ b/lib/Analysis/DereferenceChecker.cpp
@@ -56,8 +56,7 @@
                                        SVal l) {
   // Check for dereference of an undefined value.
   if (l.isUndef()) {
-    ExplodedNode *N = C.GenerateNode(S, true);
-    if (N) {
+    if (ExplodedNode *N = C.GenerateSink()) {
       if (!BT_undef)
         BT_undef = new BuiltinBug("Dereference of undefined pointer value");
       
@@ -84,7 +83,7 @@
   if (nullState) {
     if (!notNullState) {    
       // Generate an error node.
-      ExplodedNode *N = C.GenerateNode(S, nullState, true);
+      ExplodedNode *N = C.GenerateSink(nullState);
       if (!N)
         return;
       
@@ -106,13 +105,11 @@
       // Otherwise, we have the case where the location could either be
       // null or not-null.  Record the error node as an "implicit" null
       // dereference.      
-      if (ExplodedNode *N = C.GenerateNode(S, nullState, true))
+      if (ExplodedNode *N = C.GenerateSink(nullState))
         ImplicitNullDerefNodes.push_back(N);
     }
   }
   
   // From this point forward, we know that the location is not null.
-  assert(notNullState);
-  C.addTransition(state != nullState ? C.GenerateNode(S, notNullState) :
-                                       C.getPredecessor());
+  C.addTransition(notNullState);
 }
diff --git a/lib/Analysis/DivZeroChecker.cpp b/lib/Analysis/DivZeroChecker.cpp
index a8630f1..4052637 100644
--- a/lib/Analysis/DivZeroChecker.cpp
+++ b/lib/Analysis/DivZeroChecker.cpp
@@ -63,7 +63,7 @@
   llvm::tie(stateNotZero, stateZero) = CM.AssumeDual(C.getState(), *DV);
 
   if (stateZero && !stateNotZero) {
-    if (ExplodedNode *N = C.GenerateNode(B, stateZero, true)) {
+    if (ExplodedNode *N = C.GenerateSink(stateZero)) {
       if (!BT)
         BT = new BuiltinBug("Division by zero");
 
@@ -80,6 +80,5 @@
 
   // If we get here, then the denom should not be zero. We abandon the implicit
   // zero denom case for now.
-  if (stateNotZero != C.getState())
-    C.addTransition(C.GenerateNode(B, stateNotZero));
+  C.addTransition(stateNotZero);
 }
diff --git a/lib/Analysis/FixedAddressChecker.cpp b/lib/Analysis/FixedAddressChecker.cpp
index 80096dc..d8adaaf 100644
--- a/lib/Analysis/FixedAddressChecker.cpp
+++ b/lib/Analysis/FixedAddressChecker.cpp
@@ -53,7 +53,7 @@
   if (!RV.isConstant() || RV.isZeroConstant())
     return;
 
-  if (ExplodedNode *N = C.GenerateNode(B)) {
+  if (ExplodedNode *N = C.GenerateNode()) {
     if (!BT)
       BT = new BuiltinBug("Use fixed address", 
                           "Using a fixed address is not portable because that "
diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index 4f3440d..f657aeb 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -1292,9 +1292,13 @@
     Checker *checker = I->second;
     
     for (ExplodedNodeSet::iterator NI = PrevSet->begin(), NE = PrevSet->end();
-         NI != NE; ++NI)
-      checker->GR_VisitLocation(*CurrSet, *Builder, *this, S, *NI, state,
+         NI != NE; ++NI) {
+      // Use the 'state' argument only when the predecessor node is the
+      // same as Pred.  This allows us to catch updates to the state.
+      checker->GR_VisitLocation(*CurrSet, *Builder, *this, S, *NI,
+                                *NI == Pred ? state : GetState(*NI),
                                 location, tag, isLoad);
+    }
     
     // Update which NodeSet is the current one.
     PrevSet = CurrSet;
diff --git a/lib/Analysis/MallocChecker.cpp b/lib/Analysis/MallocChecker.cpp
index 995720b..a16125d 100644
--- a/lib/Analysis/MallocChecker.cpp
+++ b/lib/Analysis/MallocChecker.cpp
@@ -112,9 +112,7 @@
   SymbolRef Sym = CallVal.getAsLocSymbol();
   assert(Sym);
   // Set the symbol's state to Allocated.
-  const GRState *AllocState 
-    = state->set<RegionState>(Sym, RefState::getAllocated(CE));
-  C.addTransition(C.GenerateNode(CE, AllocState));
+  C.addTransition(state->set<RegionState>(Sym, RefState::getAllocated(CE)));
 }
 
 void MallocChecker::FreeMem(CheckerContext &C, const CallExpr *CE) {
@@ -128,7 +126,7 @@
 
   // Check double free.
   if (RS->isReleased()) {
-    ExplodedNode *N = C.GenerateNode(CE, true);
+    ExplodedNode *N = C.GenerateSink();
     if (N) {
       if (!BT_DoubleFree)
         BT_DoubleFree = new BuiltinBug("Double free",
@@ -144,7 +142,7 @@
   // Normal free.
   const GRState *FreedState 
     = state->set<RegionState>(Sym, RefState::getReleased(CE));
-  C.addTransition(C.GenerateNode(CE, FreedState));
+  C.addTransition(FreedState);
 }
 
 void MallocChecker::EvalDeadSymbols(CheckerContext &C, const Stmt *S,
@@ -158,7 +156,7 @@
       return;
 
     if (RS->isAllocated()) {
-      ExplodedNode *N = C.GenerateNode(S, true);
+      ExplodedNode *N = C.GenerateSink();
       if (N) {
         if (!BT_Leak)
           BT_Leak = new BuiltinBug("Memory leak",
@@ -213,7 +211,5 @@
   if (RS->isAllocated())
     state = state->set<RegionState>(Sym, RefState::getEscaped(S));
 
-  ExplodedNode *N = C.GenerateNode(S, state);
-  if (N)
-    C.addTransition(N);
+  C.addTransition(state);
 }
diff --git a/lib/Analysis/PointerArithChecker.cpp b/lib/Analysis/PointerArithChecker.cpp
index 9382348..6bf1a3f 100644
--- a/lib/Analysis/PointerArithChecker.cpp
+++ b/lib/Analysis/PointerArithChecker.cpp
@@ -53,7 +53,7 @@
   if (isa<VarRegion>(LR) || isa<CodeTextRegion>(LR) || 
       isa<CompoundLiteralRegion>(LR)) {
 
-    if (ExplodedNode *N = C.GenerateNode(B)) {
+    if (ExplodedNode *N = C.GenerateNode()) {
       if (!BT)
         BT = new BuiltinBug("Dangerous pointer arithmetic",
                             "Pointer arithmetic done on non-array variables "
diff --git a/lib/Analysis/PointerSubChecker.cpp b/lib/Analysis/PointerSubChecker.cpp
index 4c7906f..50f5025 100644
--- a/lib/Analysis/PointerSubChecker.cpp
+++ b/lib/Analysis/PointerSubChecker.cpp
@@ -61,7 +61,7 @@
   if (isa<SymbolicRegion>(BaseLR) || isa<SymbolicRegion>(BaseRR))
     return;
 
-  if (ExplodedNode *N = C.GenerateNode(B)) {
+  if (ExplodedNode *N = C.GenerateNode()) {
     if (!BT)
       BT = new BuiltinBug("Pointer subtraction", 
                           "Subtraction of two pointers that do not point to "
diff --git a/lib/Analysis/ReturnPointerRangeChecker.cpp b/lib/Analysis/ReturnPointerRangeChecker.cpp
index 44887b2..8a19294 100644
--- a/lib/Analysis/ReturnPointerRangeChecker.cpp
+++ b/lib/Analysis/ReturnPointerRangeChecker.cpp
@@ -70,7 +70,7 @@
   const GRState *StInBound = state->AssumeInBound(Idx, NumElements, true);
   const GRState *StOutBound = state->AssumeInBound(Idx, NumElements, false);
   if (StOutBound && !StInBound) {
-    ExplodedNode *N = C.GenerateNode(RS, StOutBound, true);
+    ExplodedNode *N = C.GenerateSink(StOutBound);
 
     if (!N)
       return;
@@ -91,7 +91,6 @@
       new RangedBugReport(*BT, BT->getDescription(), N);
 
     report->addRange(RetE->getSourceRange());
-
     C.EmitReport(report);
   }
 }
diff --git a/lib/Analysis/ReturnStackAddressChecker.cpp b/lib/Analysis/ReturnStackAddressChecker.cpp
index e4be871..e8a014a 100644
--- a/lib/Analysis/ReturnStackAddressChecker.cpp
+++ b/lib/Analysis/ReturnStackAddressChecker.cpp
@@ -53,7 +53,7 @@
   if (!R || !R->hasStackStorage())
     return;  
   
-  ExplodedNode *N = C.GenerateNode(RS, C.getState(), true);
+  ExplodedNode *N = C.GenerateSink();
 
   if (!N)
     return;
diff --git a/lib/Analysis/ReturnUndefChecker.cpp b/lib/Analysis/ReturnUndefChecker.cpp
index 796c760..48163b4 100644
--- a/lib/Analysis/ReturnUndefChecker.cpp
+++ b/lib/Analysis/ReturnUndefChecker.cpp
@@ -50,7 +50,7 @@
   if (!C.getState()->getSVal(RetE).isUndef())
     return;
   
-  ExplodedNode *N = C.GenerateNode(RS, C.getState(), true);
+  ExplodedNode *N = C.GenerateSink();
 
   if (!N)
     return;
diff --git a/lib/Analysis/UndefinedArgChecker.cpp b/lib/Analysis/UndefinedArgChecker.cpp
index ea7d971..e717f6b 100644
--- a/lib/Analysis/UndefinedArgChecker.cpp
+++ b/lib/Analysis/UndefinedArgChecker.cpp
@@ -47,7 +47,7 @@
 
 void UndefinedArgChecker::EmitBadCall(BugType *BT, CheckerContext &C,
                                       const CallExpr *CE) {
-  ExplodedNode *N = C.GenerateNode(CE, true);
+  ExplodedNode *N = C.GenerateSink();
   if (!N)
     return;
     
@@ -81,7 +81,7 @@
   for (CallExpr::const_arg_iterator I = CE->arg_begin(), E = CE->arg_end();
        I != E; ++I) {
     if (C.getState()->getSVal(*I).isUndef()) {
-      if (ExplodedNode *N = C.GenerateNode(CE, true)) {
+      if (ExplodedNode *N = C.GenerateSink()) {
         if (!BT_call_arg)
           BT_call_arg = new BuiltinBug("Pass-by-value argument in function call"
                                        " is undefined");
@@ -104,7 +104,7 @@
 
   if (const Expr *receiver = ME->getReceiver())
     if (state->getSVal(receiver).isUndef()) {
-      if (ExplodedNode *N = C.GenerateNode(ME, true)) {
+      if (ExplodedNode *N = C.GenerateSink()) {
         if (!BT_msg_undef)
           BT_msg_undef =
             new BuiltinBug("Receiver in message expression is a garbage value");
@@ -122,7 +122,7 @@
   for (ObjCMessageExpr::const_arg_iterator I = ME->arg_begin(), E = ME->arg_end();
        I != E; ++I) {
     if (state->getSVal(*I).isUndef()) {
-      if (ExplodedNode *N = C.GenerateNode(ME, true)) {
+      if (ExplodedNode *N = C.GenerateSink()) {
         if (!BT_msg_arg)
           BT_msg_arg =
             new BuiltinBug("Pass-by-value argument in message expression"
diff --git a/lib/Analysis/UndefinedArraySubscriptChecker.cpp b/lib/Analysis/UndefinedArraySubscriptChecker.cpp
index 887c775..3ae0c57 100644
--- a/lib/Analysis/UndefinedArraySubscriptChecker.cpp
+++ b/lib/Analysis/UndefinedArraySubscriptChecker.cpp
@@ -41,7 +41,7 @@
 UndefinedArraySubscriptChecker::PreVisitArraySubscriptExpr(CheckerContext &C, 
                                                 const ArraySubscriptExpr *A) {
   if (C.getState()->getSVal(A->getIdx()).isUndef()) {
-    if (ExplodedNode *N = C.GenerateNode(A, true)) {
+    if (ExplodedNode *N = C.GenerateSink()) {
       if (!BT)
         BT = new BuiltinBug("Array subscript is undefined");
 
diff --git a/lib/Analysis/UndefinedAssignmentChecker.cpp b/lib/Analysis/UndefinedAssignmentChecker.cpp
index 0e911ff..1c5b25c 100644
--- a/lib/Analysis/UndefinedAssignmentChecker.cpp
+++ b/lib/Analysis/UndefinedAssignmentChecker.cpp
@@ -48,7 +48,7 @@
   if (!val.isUndef())
     return;
 
-  ExplodedNode *N = C.GenerateNode(StoreE, true);
+  ExplodedNode *N = C.GenerateSink();
 
   if (!N)
     return;
diff --git a/lib/Analysis/VLASizeChecker.cpp b/lib/Analysis/VLASizeChecker.cpp
index 799a73e..9a3436c 100644
--- a/lib/Analysis/VLASizeChecker.cpp
+++ b/lib/Analysis/VLASizeChecker.cpp
@@ -55,7 +55,7 @@
 
   if (sizeV.isUndef()) {
     // Generate an error node.
-    ExplodedNode *N = C.GenerateNode(DS, true);    
+    ExplodedNode *N = C.GenerateSink();
     if (!N)
       return;
     
@@ -78,7 +78,7 @@
   llvm::tie(stateNotZero, stateZero) = state->Assume(sizeD);
 
   if (stateZero && !stateNotZero) {
-    ExplodedNode* N = C.GenerateNode(DS, stateZero, true);
+    ExplodedNode* N = C.GenerateSink(stateZero);
     if (!BT_zero)
       BT_zero = new BuiltinBug("Declared variable-length array (VLA) has zero "
                                "size");
@@ -92,6 +92,5 @@
   }
  
   // From this point on, assume that the size is not zero.
-  if (state != stateNotZero)
-    C.addTransition(C.GenerateNode(DS, stateNotZero));  
+  C.addTransition(stateNotZero);
 }