diff -r 9046db64ca39 -r cddef3bde924 src/hotspot/share/oops/instanceKlass.cpp
--- a/src/hotspot/share/oops/instanceKlass.cpp	Wed Sep 11 14:16:27 2019 +0200
+++ b/src/hotspot/share/oops/instanceKlass.cpp	Wed Sep 11 14:16:30 2019 +0200
@@ -2546,7 +2546,7 @@
   // unreference array name derived from this class name (arrays of an unloaded
   // class can't be referenced anymore).
   if (_array_name != NULL)  _array_name->decrement_refcount();
-  if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension);
+  FREE_C_HEAP_ARRAY(char, _source_debug_extension);
 }
 
 void InstanceKlass::set_source_debug_extension(const char* array, int length) {