Fix false negative reported in PR 10358 by using 'Unknown' in -Wuninitialized to avoid cascading warnings.  Patch by Kaelyn Uhrain.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135217 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp
index 1d6959d..5e00eeb 100644
--- a/lib/Analysis/UninitializedValues.cpp
+++ b/lib/Analysis/UninitializedValues.cpp
@@ -495,9 +495,11 @@
 
       ValueVector::reference val = vals[vd];
       if (isUninitialized(val)) {
-        if (bo->getOpcode() != BO_Assign)
+        if (bo->getOpcode() != BO_Assign) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
-        val = Initialized;
+          val = Unknown;
+        } else
+          val = Initialized;
       }
       return;
     }
@@ -526,7 +528,7 @@
         if (isUninitialized(val)) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
           // Don't cascade warnings.
-          val = Initialized;
+          val = Unknown;
         }
         return;
       }
@@ -558,7 +560,7 @@
         if (isUninitialized(val)) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
           // Don't cascade warnings.
-          vals[vd] = Initialized;
+          vals[vd] = Unknown;
         }
       }
       return;