diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -544,6 +544,7 @@
   DiagnosticsEngine &operator=(const DiagnosticsEngine &) = delete;
   ~DiagnosticsEngine();
 
+  friend void DiagnosticTestHelper(DiagnosticsEngine &);
   LLVM_DUMP_METHOD void dump() const;
   LLVM_DUMP_METHOD void dump(StringRef DiagName) const;
 
@@ -887,9 +888,9 @@
     LastDiagLevel = Other.LastDiagLevel;
   }
 
-  /// Reset the state of the diagnostic object to its initial
-  /// configuration.
-  void Reset();
+  /// Reset the state of the diagnostic object to its initial configuration.
+  /// \param[in] soft - if true, doesn't reset the diagnostic mappings and state
+  void Reset(bool soft = false);
 
   //===--------------------------------------------------------------------===//
   // DiagnosticsEngine classification and reporting interfaces.
diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -130,7 +130,7 @@
   return true;
 }
 
-void DiagnosticsEngine::Reset() {
+void DiagnosticsEngine::Reset(bool soft /*=false*/) {
   ErrorOccurred = false;
   UncompilableErrorOccurred = false;
   FatalErrorOccurred = false;
@@ -145,15 +145,17 @@
   LastDiagLevel = DiagnosticIDs::Ignored;
   DelayedDiagID = 0;
 
-  // Clear state related to #pragma diagnostic.
-  DiagStates.clear();
-  DiagStatesByLoc.clear();
-  DiagStateOnPushStack.clear();
+  if (!soft) {
+    // Clear state related to #pragma diagnostic.
+    DiagStates.clear();
+    DiagStatesByLoc.clear();
+    DiagStateOnPushStack.clear();
 
-  // Create a DiagState and DiagStatePoint representing diagnostic changes
-  // through command-line.
-  DiagStates.emplace_back();
-  DiagStatesByLoc.appendFirst(&DiagStates.back());
+    // Create a DiagState and DiagStatePoint representing diagnostic changes
+    // through command-line.
+    DiagStates.emplace_back();
+    DiagStatesByLoc.appendFirst(&DiagStates.back());
+  }
 }
 
 void DiagnosticsEngine::SetDelayedDiagnostic(unsigned DiagID, StringRef Arg1,
diff --git a/clang/test/Interpreter/error-recovery-pragmas.cpp b/clang/test/Interpreter/error-recovery-pragmas.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/Interpreter/error-recovery-pragmas.cpp
@@ -0,0 +1,6 @@
+// RUN: cat %s | clang-repl -Xcc -Xclang -Xcc -verify
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wmultichar"
+// Reset should not delete #pragmas
+error; // expected-error {{use of undeclared identifier}}
+void no_diag_multichar(void) { char c = (char)'ab'; }
diff --git a/clang/tools/clang-repl/ClangRepl.cpp b/clang/tools/clang-repl/ClangRepl.cpp
--- a/clang/tools/clang-repl/ClangRepl.cpp
+++ b/clang/tools/clang-repl/ClangRepl.cpp
@@ -86,14 +86,17 @@
       llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "error: ");
   }
 
+  bool hadErrors = false;
   if (OptInputs.empty()) {
     llvm::LineEditor LE("clang-repl");
     // FIXME: Add LE.setListCompleter
     while (llvm::Optional<std::string> Line = LE.readLine()) {
       if (*Line == "quit")
         break;
-      if (auto Err = Interp->ParseAndExecute(*Line))
+      if (auto Err = Interp->ParseAndExecute(*Line)) {
         llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "error: ");
+        hadErrors = true;
+      }
     }
   }
 
@@ -104,5 +107,5 @@
 
   llvm::llvm_shutdown();
 
-  return 0;
+  return hadErrors;
 }
diff --git a/clang/unittests/Basic/DiagnosticTest.cpp b/clang/unittests/Basic/DiagnosticTest.cpp
--- a/clang/unittests/Basic/DiagnosticTest.cpp
+++ b/clang/unittests/Basic/DiagnosticTest.cpp
@@ -14,6 +14,15 @@
 using namespace llvm;
 using namespace clang;
 
+void clang::DiagnosticsTestHelper(DiagnosticsEngine &diag) {
+  unsigned delayedDiagID = 0U;
+
+  EXPECT_EQ(diag.DelayedDiagID, delayedDiagID);
+  EXPECT_FALSE(diag.DiagStates.empty());
+  EXPECT_TRUE(diag.DiagStatesByLoc.empty());
+  EXPECT_TRUE(diag.DiagStateOnPushStack.empty());
+}
+
 namespace {
 
 // Check that DiagnosticErrorTrap works with SuppressAllDiagnostics.
@@ -71,6 +80,32 @@
     EXPECT_EQ(Diags.getNumWarnings(), FatalsAsError);
   }
 }
+
+// Check that soft RESET works as intended
+TEST(DiagnosticTest, softReset) {
+  DiagnosticsEngine Diags(new DiagnosticIDs(), new DiagnosticOptions,
+                          new IgnoringDiagConsumer());
+
+  unsigned numWarnings = 0U, numErrors = 0U;
+
+  Diags.Reset(true);
+  // Check For ErrorOccurred and TrapNumErrorsOccurred
+  EXPECT_FALSE(Diags.hasErrorOccurred());
+  EXPECT_FALSE(Diags.hasFatalErrorOccurred());
+  EXPECT_FALSE(Diags.hasUncompilableErrorOccurred());
+  // Check for UnrecoverableErrorOccurred and TrapNumUnrecoverableErrorsOccurred
+  EXPECT_FALSE(Diags.hasUnrecoverableErrorOccurred());
+
+  EXPECT_EQ(Diags.getNumWarnings(), numWarnings);
+  EXPECT_EQ(Diags.getNumErrors(), numErrors);
+
+  // Check for private variables of DiagnosticsEngine differentiating soft reset
+  DiagnosticTestHelper(Diags);
+
+  EXPECT_FALSE(Diags.isDiagnosticInFlight());
+  EXPECT_TRUE(Diags.isLastDiagnosticIgnored());
+}
+
 TEST(DiagnosticTest, diagnosticError) {
   DiagnosticsEngine Diags(new DiagnosticIDs(), new DiagnosticOptions,
                           new IgnoringDiagConsumer());