Don't attempt to create a string from nullptr if demangling fails

1 files changed, 4 insertions, 1 deletions

diff --git a/vespalib/src/vespa/vespalib/util/classname.cpp b/vespalib/src/vespa/vespalib/util/classname.cpp
index f1dd9de6686..8e9fa6b7041 100644
--- a/vespalib/src/vespa/vespalib/util/classname.cpp
+++ b/vespalib/src/vespa/vespalib/util/classname.cpp
@@ -8,7 +8,10 @@ namespace vespalib {
 string demangle(const char * native) {
     int status = 0;
     size_t size = 0;
-    char *unmangled = abi::__cxa_demangle(native, 0, &size, &status);
+    char *unmangled = abi::__cxa_demangle(native, nullptr, &size, &status);
+    if (unmangled == nullptr) {
+        return ""; // Demangling failed for some reason. TODO return `native` instead?
+    }
     string result(unmangled);
     free(unmangled);
     return result;