fix missing Local assignments /Bytecodefrontend

sootup.core/src/main/java/sootup/core/jimple/common/constant/ClassConstant.java

@@ -167,6 +167,7 @@ public int hashCode() {
     return value.hashCode();
   }
 
+  @Nonnull
   public String getValue() {
     return value;
   }

sootup.java.bytecode/src/main/java/sootup/java/bytecode/frontend/AsmClassSource.java

@@ -168,7 +168,7 @@ public Optional<? extends ClassType> resolveSuperclass() {
     if (classNode.superName == null) {
       return Optional.empty();
     }
-    return Optional.ofNullable(AsmUtil.toJimpleClassType(classNode.superName));
+    return Optional.of(AsmUtil.toJimpleClassType(classNode.superName));
   }
 
   @Nonnull

sootup.java.bytecode/src/main/java/sootup/java/bytecode/frontend/AsmJavaClassProvider.java

@@ -59,7 +59,17 @@ public Optional<SootClassSource<JavaSootClass>> createClassSource(
     SootClassNode classNode = new SootClassNode(analysisInputLocation);
 
     try {
-      AsmUtil.initAsmClassSource(sourcePath, classNode);
+      final String actualClassSignatureStr =
+          AsmUtil.initAsmClassSource(sourcePath, classNode).replace('/', '.');
+      if (!actualClassSignatureStr.equals(
+          classType.getFullyQualifiedName())) { // in >Java9 omit the module part of the signature
+        throw new IllegalArgumentException(
+            "The given Classtype '"
+                + classType
+                + "' did not match the found ClassType in the compilation unit '"
+                + actualClassSignatureStr
+                + "'. Possibly the AnalysisInputLocation points to a subfolder already including the PackageName directory while the ClassType you wanted to retrieve is missing a PackageName.");
+      }
     } catch (IOException | IllegalArgumentException exception) {
       logger.warn(
           "ASM could not resolve class source of "
@@ -72,6 +82,7 @@ public Optional<SootClassSource<JavaSootClass>> createClassSource(
     }
 
     JavaClassType klassType = (JavaClassType) classType;
+
     if (klassType instanceof ModuleJavaClassType
         && klassType.getClassName().equals(JavaModuleIdentifierFactory.MODULE_INFO_FILE)) {
       logger.warn("Can not create ClassSource from a module info descriptor! path:" + sourcePath);