PR43674: fix incorrect constant evaluation of 'switch' where no case
label corresponds to the condition.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374954 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 4459335..a379a33 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -4435,7 +4435,7 @@
   }
 
   if (!Found)
-    return Scope.destroy() ? ESR_Failed : ESR_Succeeded;
+    return Scope.destroy() ? ESR_Succeeded : ESR_Failed;
 
   // Search the switch body for the switch case and evaluate it from there.
   EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found);
diff --git a/test/SemaCXX/constant-expression-cxx1y.cpp b/test/SemaCXX/constant-expression-cxx1y.cpp
index 2a8304e..614b395 100644
--- a/test/SemaCXX/constant-expression-cxx1y.cpp
+++ b/test/SemaCXX/constant-expression-cxx1y.cpp
@@ -627,6 +627,12 @@
 }
 
 namespace switch_stmt {
+  constexpr bool no_such_case(int n) {
+    switch (n) { case 1: return false; }
+    return true;
+  }
+  static_assert(no_such_case(0), "");
+
   constexpr int f(char k) {
     bool b = false;
     int z = 6;