From e97d558ce961922845c2ecb116a2d858e3cf0ed0 Mon Sep 17 00:00:00 2001
From: Nico Weber <nicolasweber@gmx.de>
Date: Thu, 11 Apr 2019 22:59:25 +0000
Subject: [PATCH] llvm-undname: Don't crash on incomplete enum tag manglings

Found by inspection.

llvm-svn: 358238
---
 lib/Demangle/MicrosoftDemangle.cpp   | 2 +-
 test/Demangle/invalid-manglings.test | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/Demangle/MicrosoftDemangle.cpp b/lib/Demangle/MicrosoftDemangle.cpp
index f45df9413d7..c4559ccb5e2 100644
--- a/lib/Demangle/MicrosoftDemangle.cpp
+++ b/lib/Demangle/MicrosoftDemangle.cpp
@@ -1907,7 +1907,7 @@ TagTypeNode *Demangler::demangleClassType(StringView &MangledName) {
     TT = Arena.alloc<TagTypeNode>(TagKind::Class);
     break;
   case 'W':
-    if (MangledName.popFront() != '4') {
+    if (!MangledName.consumeFront('4')) {
       Error = true;
       return nullptr;
     }
diff --git a/test/Demangle/invalid-manglings.test b/test/Demangle/invalid-manglings.test
index 4c155b765a4..839218ad101 100644
--- a/test/Demangle/invalid-manglings.test
+++ b/test/Demangle/invalid-manglings.test
@@ -104,3 +104,8 @@
 ; CHECK-EMPTY:
 ; CHECK-NEXT: ??C@$
 ; CHECK-NEXT: error: Invalid mangled name
+
+?x@@3PAW
+; CHECK-EMPTY:
+; CHECK-NEXT: ?x@@3PAW
+; CHECK-NEXT: error: Invalid mangled name