fix multi line description in allOf (#17879)

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

@@ -4214,7 +4214,8 @@ public class DefaultCodegen implements CodegenConfig {
                 property.deprecated = p.getDeprecated();
             }
             if (original.getDescription() != null) {
-                property.description = p.getDescription();
+                property.description = escapeText(p.getDescription());
+                property.unescapedDescription = p.getDescription();
             }
             if (original.getMaxLength() != null) {
                 property.setMaxLength(original.getMaxLength());

modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml

@@ -2577,6 +2577,10 @@ components:
           format: int64
           x-is-unique: true
         category:
+          description: |
+            multi line description
+            2nd line
+            last line
           allOf:
             - $ref: '#/components/schemas/Category'
         name:
@@ -2603,4 +2607,4 @@ components:
           enum:
             - available
             - pending
-            - sold
+            - sold

samples/client/petstore/java/okhttp-gson/api/openapi.yaml

@@ -2560,6 +2560,10 @@ components:
         category:
           allOf:
           - $ref: '#/components/schemas/Category'
+          description: |
+            multi line description
+            2nd line
+            last line
         name:
           example: doggie
           type: string

samples/client/petstore/java/okhttp-gson/docs/PetUsingAllOf.md

@@ -8,7 +8,7 @@
 | Name | Type | Description | Notes |
 |------------ | ------------- | ------------- | -------------|
 |**id** | **Long** |  |  [optional] |
-|**category** | [**Category**](Category.md) |  |  [optional] |
+|**category** | [**Category**](Category.md) | multi line description 2nd line last line  |  [optional] |
 |**name** | **String** |  |  |
 |**photoUrls** | **List<String>** |  |  |
 |**tags** | [**List<Tag>**](Tag.md) |  |  [optional] |

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java

@@ -161,7 +161,7 @@ public class PetUsingAllOf {
   }
 
    /**
-   * Get category
+   * multi line description 2nd line last line 
    * @return category
   **/
   @javax.annotation.Nullable