llvm-undname: Fix crash on invalid name in a template parameter pointer to member arg

Found by oss-fuzz.

llvm-svn: 358234

2 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Demangle/MicrosoftDemangle.cpp b/llvm/lib/Demangle/MicrosoftDemangle.cpp
index c649552051f..194a152acb8 100644
--- a/llvm/lib/Demangle/MicrosoftDemangle.cpp
+++ b/llvm/lib/Demangle/MicrosoftDemangle.cpp
@@ -2139,6 +2139,8 @@ Demangler::demangleTemplateParameterList(StringView &MangledName) {
       SymbolNode *S = nullptr;
       if (MangledName.startsWith('?')) {
         S = parse(MangledName);
+        if (Error)
+          return nullptr;
         memorizeIdentifier(S->Name->getUnqualifiedIdentifier());
       }
 
diff --git a/llvm/test/Demangle/invalid-manglings.test b/llvm/test/Demangle/invalid-manglings.test
index 40bf92df357..5d6f3160a95 100644
--- a/llvm/test/Demangle/invalid-manglings.test
+++ b/llvm/test/Demangle/invalid-manglings.test
@@ -94,3 +94,8 @@
 ; CHECK-EMPTY:
 ; CHECK-NEXT: ??8@8
 ; CHECK-NEXT: error: Invalid mangled name
+
+?B@?$?K$H?
+; CHECK-EMPTY:
+; CHECK-NEXT: ?B@?$?K$H?
+; CHECK-NEXT: error: Invalid mangled name