diff --git a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index b10c80a..a7655c4 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -632,6 +632,7 @@
   RegionStateTy RS = state->get<RegionState>();
 
   for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
+    // If the symbol is assumed to NULL, this will return an APSInt*.
     if (state->getSymVal(I.getKey()))
       state = state->set<RegionState>(I.getKey(),RefState::getAllocateFailed());
   }