refactor: Remove unused internal field _tombstone

spec/ParseInstallation.spec.js

@@ -1295,7 +1295,6 @@ describe('Installations', () => {
   });
 
   // TODO: Look at additional tests from installation_collection_test.go:882
-  // TODO: Do we need to support _tombstone disabling of installations?
   // TODO: Test deletion, badge increments
 
   describe('deviceToken deduplication on new install (no installationId match)', () => {

spec/RestQuery.spec.js

@@ -198,7 +198,6 @@ describe('rest query', () => {
     const internalFields = [
       '_email_verify_token',
       '_perishable_token',
-      '_tombstone',
       '_email_verify_token_expires_at',
       '_failed_login_count',
       '_account_lockout_expires_at',
@@ -222,10 +221,11 @@ describe('rest query', () => {
     user.setUsername('user1');
     user.setPassword('password');
     await user.signUp();
-    // _tombstone is registered as an internal field but has no column in the
-    // Postgres _User table. Querying it with master key should return empty
-    // results (consistent with MongoDB behavior), not throw an error.
-    const results = await new Parse.Query(Parse.User).exists('_tombstone').find({ useMasterKey: true });
+    // _session_token is registered as an internal field but has no column in
+    // the Postgres _User table (session tokens live in _Session). Querying it
+    // with master key should return empty results (consistent with MongoDB
+    // behavior), not throw an error.
+    const results = await new Parse.Query(Parse.User).exists('_session_token').find({ useMasterKey: true });
     expect(results.length).toBe(0);
   });
 
@@ -234,7 +234,7 @@ describe('rest query', () => {
     user.setUsername('user1');
     user.setPassword('password');
     await user.signUp();
-    const count = await new Parse.Query(Parse.User).exists('_tombstone').count({ useMasterKey: true });
+    const count = await new Parse.Query(Parse.User).exists('_session_token').count({ useMasterKey: true });
     expect(count).toBe(0);
   });
 

spec/vulnerabilities.spec.js

@@ -3243,7 +3243,6 @@ describe('Vulnerabilities', () => {
           '_account_lockout_expires_at',
           '_password_changed_at',
           '_password_history',
-          '_tombstone',
           '_session_token',
         ];
 

src/Adapters/Storage/Mongo/MongoTransform.js

@@ -1154,11 +1154,16 @@ const mongoObjectToParseObject = (className, mongoObject, schema) => {
             break;
           case '_acl':
             break;
+          // `_tombstone` is a legacy field that is no longer used by Parse Server,
+          // but documents created by old Parse Server / Parse.com versions may still
+          // have it persisted. It is kept here so those documents don't fall through
+          // to the `default` branch and throw "bad key in untransform".
+          // See https://github.com/parse-community/parse-server/issues/570
+          case '_tombstone':
           case '_email_verify_token':
           case '_perishable_token':
           case '_perishable_token_expires_at':
           case '_password_changed_at':
-          case '_tombstone':
           case '_email_verify_token_expires_at':
           case '_account_lockout_expires_at':
           case '_failed_login_count':

src/Controllers/DatabaseController.js

@@ -40,7 +40,6 @@ const internalFields = {
   _account_lockout_expires_at:    { clientRead: false, masterRead: true,  masterWrite: true  },
   _password_changed_at:           { clientRead: false, masterRead: true,  masterWrite: true  },
   _password_history:              { clientRead: false, masterRead: true,  masterWrite: true  },
-  _tombstone:                     { clientRead: false, masterRead: true,  masterWrite: false },
   _session_token:                 { clientRead: false, masterRead: true,  masterWrite: false },
   /////////////////////////////////////////////////////////////////////////////////////////////
   // The following fields are not accessed by their _-prefixed name through the API;