Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -9456,6 +9456,18 @@
         SavedPendingLocalImplicitInstantiations;
   };
 
+  class PerformPendingInstantiationsRAII {
+    Sema &S;
+  public:
+    PerformPendingInstantiationsRAII(Sema &S): S(S) {} ;
+
+    ~PerformPendingInstantiationsRAII() {
+      S.PerformPendingInstantiations();
+      assert(S.PendingInstantiations.empty() &&
+             "there shouldn't be any pending instantiations");
+    }
+  };
+
   /// A helper class for building up ExtParameterInfos.
   class ExtParameterInfoBuilder {
     SmallVector<FunctionProtoType::ExtParameterInfo, 16> Infos;
Index: clang/lib/Interpreter/IncrementalParser.cpp
===================================================================
--- clang/lib/Interpreter/IncrementalParser.cpp
+++ clang/lib/Interpreter/IncrementalParser.cpp
@@ -177,6 +177,7 @@
   }
 
   DiagnosticsEngine &Diags = getCI()->getDiagnostics();
+  Sema::PerformPendingInstantiationsRAII PerformPendingInstantiations(S);
   if (Diags.hasErrorOccurred()) {
     TranslationUnitDecl *MostRecentTU = C.getTranslationUnitDecl();

Index: clang/test/Interpreter/execute.cpp
===================================================================
--- clang/test/Interpreter/execute.cpp
+++ clang/test/Interpreter/execute.cpp
@@ -1,3 +1,5 @@
+// RUN: clang-repl "template<class T> T f() { return T(); }" "auto ptu2 = f<float>(); err;" \
+// RUN: "auto ptu2 = f<float>();" "int i = 0;"
 // RUN: clang-repl "int i = 10;" 'extern "C" int printf(const char*,...);' \
 // RUN:            'auto r1 = printf("i = %d\n", i);' | FileCheck --check-prefix=CHECK-DRIVER %s
 // REQUIRES: host-supports-jit