GP-6100 - PDB - fixed NPE due to function null container class

Author: ghizard

Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/DefaultPdbApplicator.java

@@ -2228,6 +2228,9 @@ boolean isClass(SymbolPath path) {
 
 	//==============================================================================================
 	void predefineClass(SymbolPath classPath) {
+		if (classPath == null) {
+			return;
+		}
 		isClassByNamespace.put(classPath, true);
 		for (SymbolPath path = classPath.getParent(); path != null; path = path.getParent()) {
 			if (!isClassByNamespace.containsKey(path)) {