From 24f20941e5d1627c56ee3b5d69d08b45f85568af Mon Sep 17 00:00:00 2001
From: William Cheng <wing328hk@gmail.com>
Date: Sat, 2 Mar 2019 21:48:00 +0800
Subject: [PATCH] fix npe when array item missing (#2247)

---
 .../org/openapitools/codegen/CodegenModel.java     | 14 +++++++++-----
 .../org/openapitools/codegen/DefaultCodegen.java   |  8 +++++++-
 .../org/openapitools/codegen/utils/ModelUtils.java |  9 ++++++++-
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
index 7480ef94b00..987fe692606 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
@@ -621,11 +621,15 @@ public class CodegenModel {
      */
     public void removeSelfReferenceImport() {
         for (CodegenProperty cp : allVars) {
-            // detect self import
-            if (cp.dataType.equalsIgnoreCase(this.classname) ||
-                    (cp.isContainer && cp.items.dataType.equalsIgnoreCase(this.classname))) {
-                this.imports.remove(this.classname); // remove self import
-                cp.isSelfReference = true;
+            if (cp == null) {
+                // TODO cp shouldn't be null. Show a warning message instead
+            } else {
+                // detect self import
+                if (this.classname.equalsIgnoreCase(cp.dataType) ||
+                        (cp.isContainer && cp.items != null && this.classname.equalsIgnoreCase(cp.items.dataType))) {
+                    this.imports.remove(this.classname); // remove self import
+                    cp.isSelfReference = true;
+                }
             }
         }
     }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index e41d05e48f4..b4142f360fd 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -257,7 +257,7 @@ public class DefaultCodegen implements CodegenConfig {
                 for (CodegenProperty cp : cm.allVars) {
                     // detect self import
                     if (cp.dataType.equalsIgnoreCase(cm.classname) ||
-                            (cp.isContainer && cp.items.dataType.equalsIgnoreCase(cm.classname))) {
+                            (cp.isContainer && cp.items != null && cp.items.dataType.equalsIgnoreCase(cm.classname))) {
                         cm.imports.remove(cm.classname); // remove self import
                         cp.isSelfReference = true;
                     }
@@ -1507,10 +1507,16 @@ public class DefaultCodegen implements CodegenConfig {
      * @return a string presentation of the property type
      */
     public String getTypeDeclaration(Schema schema) {
+        if (schema == null) {
+            LOGGER.warn("Null schema found. Default type to `NULL_SCHMEA_ERR`");
+            return "NULL_SCHMEA_ERR";
+        }
+
         String oasType = getSchemaType(schema);
         if (typeMapping.containsKey(oasType)) {
             return typeMapping.get(oasType);
         }
+
         return oasType;
     }
 
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
index 8dedaa88c93..ce5a190af49 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
@@ -329,12 +329,19 @@ public class ModelUtils {
         if (schema instanceof MapSchema) {
             return true;
         }
+
+        if (schema == null) {
+            return false;
+        }
+
         if (schema.getAdditionalProperties() instanceof Schema) {
             return true;
         }
+
         if (schema.getAdditionalProperties() instanceof Boolean && (Boolean) schema.getAdditionalProperties()) {
             return true;
         }
+
         return false;
     }
 
@@ -343,7 +350,7 @@ public class ModelUtils {
             return true;
         }
         // assume it's an array if maxItems, minItems is set
-        if (schema.getMaxItems() != null || schema.getMinItems() != null) {
+        if (schema != null && (schema.getMaxItems() != null || schema.getMinItems() != null)) {
             return true;
         }
         return false;