Index: lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
+++ lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
@@ -488,14 +488,16 @@
   // alive
   auto RegionMap = State->get<IteratorRegionMap>();
   for (const auto Reg : RegionMap) {
-    const auto Pos = Reg.second;
-    SR.markLive(Pos.getOffset());
+    const auto Offset = Reg.second.getOffset();
+    for (auto i = Offset->symbol_begin(); i != Offset->symbol_end(); ++i)
+      SR.markLive(*i);
   }
 
   auto SymbolMap = State->get<IteratorSymbolMap>();
   for (const auto Sym : SymbolMap) {
-    const auto Pos = Sym.second;
-    SR.markLive(Pos.getOffset());
+    const auto Offset = Sym.second.getOffset();
+    for (auto i = Offset->symbol_begin(); i != Offset->symbol_end(); ++i)
+      SR.markLive(*i);
   }
 
   auto ContMap = State->get<ContainerMap>();
@@ -1159,19 +1161,23 @@
   auto &SVB = State->getStateManager().getSValBuilder();
   const auto comparison =
       SVB.evalBinOp(State, BO_EQ, nonloc::SymbolVal(Pos1.getOffset()),
-                    nonloc::SymbolVal(Pos2.getOffset()), SVB.getConditionType())
-          .getAs<DefinedSVal>();
-
-  if (comparison) {
-    auto NewState = State->assume(*comparison, Equal);
-    if (const auto CompSym = comparison->getAsSymbol()) {
-      return assumeNoOverflow(NewState, cast<SymIntExpr>(CompSym)->getLHS(), 2);
-    }
-
-    return NewState;
+                    nonloc::SymbolVal(Pos2.getOffset()),
+                    SVB.getConditionType());
+
+  assert(comparison.getAs<DefinedSVal>() &&
+    "Symbol comparison must by a `DefinedSVal`");
+
+  auto NewState = State->assume(comparison.castAs<DefinedSVal>(), Equal);
+  if (const auto CompSym = comparison.getAsSymbol()) {
+    assert(isa<SymIntExpr>(CompSym) &&
+           "Symbol comparison must be a `SymIntExpr`");
+    assert(BinaryOperator::isComparisonOp(
+               cast<SymIntExpr>(CompSym)->getOpcode()) &&
+           "Symbol comparison must be a comparison");
+    return assumeNoOverflow(NewState, cast<SymIntExpr>(CompSym)->getLHS(), 2);
   }
 
-  return State;
+  return NewState;
 }
 
 bool isZero(ProgramStateRef State, const NonLoc &Val) {
@@ -1225,14 +1231,12 @@
   auto &SVB = State->getStateManager().getSValBuilder();
 
   const auto comparison =
-      SVB.evalBinOp(State, Opc, NL1, NL2, SVB.getConditionType())
-          .getAs<DefinedSVal>();
+    SVB.evalBinOp(State, Opc, NL1, NL2, SVB.getConditionType());
 
-  if (comparison) {
-    return !State->assume(*comparison, false);
-  }
+  assert(comparison.getAs<DefinedSVal>() &&
+    "Symbol comparison must by a `DefinedSVal`");
 
-  return false;
+  return !State->assume(comparison.castAs<DefinedSVal>(), false);
 }
 
 } // namespace