Prevent ConcurrentModificationException

Author: sermler

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java

@@ -1605,11 +1605,13 @@ public ExtendedCodegenModel(CodegenModel cm) {
             if (this.discriminator != null) {
                 Set<CodegenDiscriminator.MappedModel> mappedModels = this.discriminator.getMappedModels();
                 for(CodegenDiscriminator.MappedModel mappedModel : mappedModels) {
-                    if(mappedModel.getModelName().equals(cm.classname)){
-                        this.discriminator.getMappedModels().remove(mappedModel);
-                        this.selfReferencingDiscriminatorMapping=mappedModel;
+                    if(mappedModel.getModelName().equals(cm.classname)) {
+                        this.selfReferencingDiscriminatorMapping = mappedModel;
                     }
                 }
+                if(this.selfReferencingDiscriminatorMapping != null) {
+                    this.discriminator.getMappedModels().remove(this.selfReferencingDiscriminatorMapping);
+                }
             }
         }