Add test for nested enum for php (#2989)

php/tests/generated_class_test.php

@@ -295,6 +295,12 @@ class GeneratedClassTest extends TestBase
         $this->assertEquals(TestEnum::ONE, $m->getOptionalEnum());
     }
 
+    public function testNestedEnum()
+    {
+        $m = new TestMessage();
+        $m->setOptionalNestedEnum(\Foo\TestMessage_NestedEnum::ZERO);
+    }
+
     #########################################################
     # Test float field.
     #########################################################
@@ -835,6 +841,9 @@ class GeneratedClassTest extends TestBase
         $m = new TestMessage();
         $m->setOptionalNoNamespaceMessage(new NoNameSpaceMessage());
         $m->getRepeatedNoNamespaceMessage()[] = new NoNameSpaceMessage();
+
+        $n = new NoNamespaceMessage();
+        $n->setB(NoNamespaceMessage_NestedEnum::ZERO);
     }
 
     public function testEnumWithoutNamespace()

php/tests/memory_leak_test.php

@@ -4,11 +4,13 @@
 
 require_once('generated/NoNamespaceEnum.php');
 require_once('generated/NoNamespaceMessage.php');
+require_once('generated/NoNamespaceMessage_NestedEnum.php');
 require_once('generated/PrefixTestPrefix.php');
 require_once('generated/Bar/TestInclude.php');
 require_once('generated/Foo/TestEnum.php');
 require_once('generated/Foo/TestIncludePrefixMessage.php');
 require_once('generated/Foo/TestMessage.php');
+require_once('generated/Foo/TestMessage_NestedEnum.php');
 require_once('generated/Foo/TestMessage_Sub.php');
 require_once('generated/Foo/TestPackedMessage.php');
 require_once('generated/Foo/TestPhpDoc.php');

php/tests/proto/test.proto

@@ -102,6 +102,12 @@ message TestMessage {
   NoNamespaceEnum optional_no_namespace_enum = 92;
   repeated NoNamespaceMessage repeated_no_namespace_message = 93;
   repeated NoNamespaceEnum repeated_no_namespace_enum = 94;
+
+  enum NestedEnum {
+    ZERO = 0;
+  }
+
+  NestedEnum optional_nested_enum = 101;
 }
 
 enum TestEnum {

php/tests/proto/test_no_namespace.proto

@@ -2,6 +2,11 @@ syntax = "proto3";
 
 message NoNamespaceMessage {
   int32 a = 1;
+
+  enum NestedEnum {
+    ZERO = 0;
+  }
+  NestedEnum b = 2;
 }
 
 enum NoNamespaceEnum {