Fix NPE with cpp-restsdk client generator (#1477)

* fix_cpprest_npe

* fix_code_format

Author: wing328

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

@@ -285,8 +285,8 @@ public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> o
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
         for (CodegenOperation op : operationList) {
-            for(String hdr : op.imports) {
-                if(importMapping.containsKey(hdr)) {
+            for (String hdr : op.imports) {
+                if (importMapping.containsKey(hdr)) {
                     continue;
                 }
                 operations.put("hasModelImport", true);
@@ -295,7 +295,7 @@ public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> o
         }
         return objs;
     }
-    
+
     protected boolean isFileSchema(CodegenProperty property) {
         return property.baseType.equals("HttpContent");
     }
@@ -411,7 +411,6 @@ public String getSchemaType(Schema p) {
 
     @Override
     public Map<String, Object> postProcessAllModels(final Map<String, Object> models) {
-
         final Map<String, Object> processed = super.postProcessAllModels(models);
         postProcessParentModels(models);
         return processed;
@@ -432,13 +431,18 @@ private void postProcessParentModels(final Map<String, Object> models) {
      */
     private void processParentPropertiesInChildModel(final CodegenModel parent, final CodegenModel child) {
         final Map<String, CodegenProperty> childPropertiesByName = new HashMap<>(child.vars.size());
-        for (final CodegenProperty childSchema : child.vars) {
-            childPropertiesByName.put(childSchema.name, childSchema);
+        if (child != null && child.vars != null && !child.vars.isEmpty()) {
+            for (final CodegenProperty childSchema : child.vars) {
+                childPropertiesByName.put(childSchema.name, childSchema);
+            }
         }
-        for (final CodegenProperty parentSchema : parent.vars) {
-            final CodegenProperty duplicatedByParent = childPropertiesByName.get(parentSchema.name);
-            if (duplicatedByParent != null) {
-                duplicatedByParent.isInherited = true;
+
+        if (parent != null && parent.vars != null && !parent.vars.isEmpty()) {
+            for (final CodegenProperty parentSchema : parent.vars) {
+                final CodegenProperty duplicatedByParent = childPropertiesByName.get(parentSchema.name);
+                if (duplicatedByParent != null) {
+                    duplicatedByParent.isInherited = true;
+                }
             }
         }
     }