Index: clang-tools-extra/trunk/clangd/JSONRPCDispatcher.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/JSONRPCDispatcher.cpp
+++ clang-tools-extra/trunk/clangd/JSONRPCDispatcher.cpp
@@ -278,7 +278,7 @@
       continue;
 
     // found a delimiter
-    if (LineRef.find_first_not_of('-') == llvm::StringRef::npos)
+    if (LineRef.rtrim() == "---")
       break;
 
     JSON += Line;
Index: clang-tools-extra/trunk/test/clangd/spaces-in-delimited-input.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/spaces-in-delimited-input.test
+++ clang-tools-extra/trunk/test/clangd/spaces-in-delimited-input.test
@@ -0,0 +1,13 @@
+# RUN: clangd -input-style=delimited -run-synchronously < %s 2>&1 | FileCheck %s
+# RUN: clangd -lit-test -run-synchronously < %s 2>&1 | FileCheck %s
+#
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
+
+---
+
+{"jsonrpc":"2.0","id":3,"method":"shutdown"}
+
+---
+
+{"jsonrpc":"2.0","id":3,"method":"exit"}
+# CHECK-NOT: JSON parse error