fix parent name look up using schema name (#17807)

Author: wing328

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

@@ -51,8 +51,11 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public Set<String> oneOf = new TreeSet<>();
     public Set<String> allOf = new TreeSet<>();
 
-    // The schema name as written in the OpenAPI document.
+    // The schema name as written in the OpenAPI document
+    // If it's a reserved word, it will be escaped.
     public String name;
+    // The original schema name as written in the OpenAPI document.
+    public String schemaName;
     // The language-specific name of the class that implements this schema.
     // The name of the class is derived from the OpenAPI schema name with formatting rules applied.
     // The classname is derived from the OpenAPI schema name, with sanitization and escaping rules applied.
@@ -492,6 +495,15 @@ public void setName(String name) {
         this.name = name;
     }
 
+    public String getSchemaName() {
+        return schemaName;
+    }
+
+    public void setSchemaName(String schemaName) {
+        this.schemaName = schemaName;
+    }
+
+
     public List<CodegenProperty> getOptionalVars() {
         return optionalVars;
     }
@@ -1144,6 +1156,7 @@ public boolean equals(Object o) {
                 Objects.equals(oneOf, that.oneOf) &&
                 Objects.equals(allOf, that.allOf) &&
                 Objects.equals(name, that.name) &&
+                Objects.equals(schemaName, that.schemaName) &&
                 Objects.equals(classname, that.classname) &&
                 Objects.equals(title, that.title) &&
                 Objects.equals(description, that.description) &&
@@ -1192,7 +1205,7 @@ public boolean equals(Object o) {
     @Override
     public int hashCode() {
         return Objects.hash(getParent(), getParentSchema(), getInterfaces(), getAllParents(), getParentModel(),
-                getInterfaceModels(), getChildren(), anyOf, oneOf, allOf, getName(), getClassname(), getTitle(),
+                getInterfaceModels(), getChildren(), anyOf, oneOf, allOf, getName(), getSchemaName(), getClassname(), getTitle(),
                 getDescription(), getClassVarName(), getModelJson(), getDataType(), getXmlPrefix(), getXmlNamespace(),
                 getXmlName(), getClassFilename(), getUnescapedDescription(), getDiscriminator(), getDefaultValue(),
                 getArrayModelType(), isAlias, isString, isInteger, isLong, isNumber, isNumeric, isFloat, isDouble,
@@ -1214,6 +1227,7 @@ isAnyType, getComposedSchemas(), hasMultipleTypes, isDecimal, isUuid, isUri, req
     public String toString() {
         final StringBuilder sb = new StringBuilder("CodegenModel{");
         sb.append("name='").append(name).append('\'');
+        sb.append(", schemaName='").append(schemaName).append('\'');
         sb.append(", parent='").append(parent).append('\'');
         sb.append(", parentSchema='").append(parentSchema).append('\'');
         sb.append(", interfaces=").append(interfaces);

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

@@ -667,14 +667,16 @@ public Map<String, ModelsMap> updateAllModels(Map<String, ModelsMap> objs) {
                 }
                 parent.getChildren().add(cm);
                 parent.hasChildren = true;
-                Schema parentSchema = this.openAPI.getComponents().getSchemas().get(parent.name);
+                Schema parentSchema = this.openAPI.getComponents().getSchemas().get(parent.schemaName);
                 if (parentSchema == null) {
-                    throw new NullPointerException(parent.name + " in " + this.openAPI.getComponents().getSchemas());
-                }
-                if (parentSchema.getDiscriminator() == null) {
-                    parent = allModels.get(parent.getParent());
-                } else {
+                    LOGGER.warn("Failed to look up parent schema: {}", parent.schemaName);
                     parent = null;
+                } else {
+                    if (parentSchema.getDiscriminator() == null) {
+                        parent = allModels.get(parent.getParent());
+                    } else {
+                        parent = null;
+                    }
                 }
             }
         }
@@ -3122,6 +3124,7 @@ public CodegenModel fromModel(String name, Schema schema) {
         } else {
             m.name = name;
         }
+        m.schemaName = name; // original schema name
         m.title = escapeText(schema.getTitle());
         m.description = escapeText(schema.getDescription());
         m.unescapedDescription = schema.getDescription();