Make the default behavior of getApplicationTransactionCommentObject() "return null" instead of "throw"

Summary:
Depends on D20115. See <https://discourse.phabricator-community.org/t/transaction-search-endpoint-does-not-work-on-differential-diffs/2369/>.

Currently, `getApplicationTransactionCommentObject()` throws by default. Subclasses must override it to `return null` to indicate that they don't support comments.

This is silly, and leads to a bunch of code that does a `try / catch` around it, and at least some code (here, `transaction.search`) which doesn't `try / catch` and gets the wrong behavior as a result.

Just make it `return null` by default, meaning "no support for comments". Then remove the `try / catch` stuff and all the `return null` implementations.

Test Plan:
  - Grepped for `getApplicationTransactionCommentObject()`, fixed each callsite / definition.
  - Called `transaction.search` on a diff with transactions (i.e., not a sourced-from-commit diff).

Reviewers: amckinley

Reviewed By: amckinley

Subscribers: jbrownEP

Differential Revision: https://secure.phabricator.com/D20121

src/applications/almanac/storage/AlmanacModularTransaction.php

@@ -7,8 +7,4 @@ abstract class AlmanacModularTransaction
     return 'almanac';
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
 }

src/applications/auth/storage/PhabricatorAuthPasswordTransaction.php

@@ -11,10 +11,6 @@ final class PhabricatorAuthPasswordTransaction
     return PhabricatorAuthPasswordPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhabricatorAuthPasswordTransactionType';
   }

src/applications/auth/storage/PhabricatorAuthProviderConfigTransaction.php

@@ -33,10 +33,6 @@ final class PhabricatorAuthProviderConfigTransaction
     return PhabricatorAuthAuthProviderPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getIcon() {
     $old = $this->getOldValue();
     $new = $this->getNewValue();

src/applications/auth/storage/PhabricatorAuthSSHKeyTransaction.php

@@ -15,10 +15,6 @@ final class PhabricatorAuthSSHKeyTransaction
     return PhabricatorAuthSSHKeyPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
 

src/applications/config/storage/PhabricatorConfigTransaction.php

@@ -13,10 +13,6 @@ final class PhabricatorConfigTransaction
     return PhabricatorConfigConfigPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
 

src/applications/diviner/storage/DivinerLiveBookTransaction.php

@@ -11,8 +11,4 @@ final class DivinerLiveBookTransaction
     return DivinerBookPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
 }

src/applications/fund/storage/FundBackerTransaction.php

@@ -11,10 +11,6 @@ final class FundBackerTransaction
     return FundBackerPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'FundBackerTransactionType';
   }

src/applications/herald/action/HeraldCommentAction.php

@@ -19,14 +19,11 @@ final class HeraldCommentAction extends HeraldAction {
     }
 
     $xaction = $object->getApplicationTransactionTemplate();
-    try {
+
     $comment = $xaction->getApplicationTransactionCommentObject();
     if (!$comment) {
       return false;
     }
-    } catch (PhutilMethodNotImplementedException $ex) {
-      return false;
-    }
 
     return true;
   }

src/applications/herald/storage/HeraldWebhookTransaction.php

@@ -11,10 +11,6 @@ final class HeraldWebhookTransaction
     return HeraldWebhookPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'HeraldWebhookTransactionType';
   }

src/applications/metamta/storage/PhabricatorMetaMTAApplicationEmailTransaction.php

@@ -16,8 +16,4 @@ final class PhabricatorMetaMTAApplicationEmailTransaction
     return PhabricatorMetaMTAApplicationEmailPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
 }

src/applications/oauthserver/storage/PhabricatorOAuthServerTransaction.php

@@ -19,10 +19,6 @@ final class PhabricatorOAuthServerTransaction
     return PhabricatorOAuthServerClientPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
     $old = $this->getOldValue();

src/applications/owners/storage/PhabricatorOwnersPackageTransaction.php

@@ -15,8 +15,4 @@ final class PhabricatorOwnersPackageTransaction
     return 'PhabricatorOwnersPackageTransactionType';
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
 }

src/applications/passphrase/storage/PassphraseCredentialTransaction.php

@@ -11,10 +11,6 @@ final class PassphraseCredentialTransaction
     return PassphraseCredentialPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PassphraseCredentialTransactionType';
   }

src/applications/people/storage/PhabricatorUserTransaction.php

@@ -11,10 +11,6 @@ final class PhabricatorUserTransaction
     return PhabricatorPeopleUserPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhabricatorUserTransactionType';
   }

src/applications/phame/storage/PhameBlogTransaction.php

@@ -15,10 +15,6 @@ final class PhameBlogTransaction
     return PhabricatorPhameBlogPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhameBlogTransactionType';
   }

src/applications/phlux/storage/PhluxTransaction.php

@@ -13,10 +13,6 @@ final class PhluxTransaction extends PhabricatorApplicationTransaction {
     return PhluxVariablePHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
 

src/applications/phortune/storage/PhortuneAccountTransaction.php

@@ -11,10 +11,6 @@ final class PhortuneAccountTransaction
     return PhortuneAccountPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhortuneAccountTransactionType';
   }

src/applications/phortune/storage/PhortuneCartTransaction.php

@@ -19,10 +19,6 @@ final class PhortuneCartTransaction
     return PhortuneCartPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function shouldHideForMail(array $xactions) {
     switch ($this->getTransactionType()) {
       case self::TYPE_CREATED:

src/applications/phortune/storage/PhortuneMerchantTransaction.php

@@ -11,10 +11,6 @@ final class PhortuneMerchantTransaction
     return PhortuneMerchantPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhortuneMerchantTransactionType';
   }

src/applications/phortune/storage/PhortunePaymentProviderConfigTransaction.php

@@ -17,10 +17,6 @@ final class PhortunePaymentProviderConfigTransaction
     return PhortunePaymentProviderPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
 

src/applications/project/storage/PhabricatorProjectTransaction.php

@@ -19,10 +19,6 @@ final class PhabricatorProjectTransaction
     return PhabricatorProjectProjectPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhabricatorProjectTransactionType';
   }

src/applications/repository/storage/PhabricatorRepositoryTransaction.php

@@ -11,10 +11,6 @@ final class PhabricatorRepositoryTransaction
     return PhabricatorRepositoryRepositoryPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhabricatorRepositoryTransactionType';
   }

src/applications/search/engineextension/PhabricatorFulltextIndexEngineExtension.php

@@ -70,14 +70,10 @@ final class PhabricatorFulltextIndexEngineExtension
   private function getCommentVersion($object) {
     $xaction = $object->getApplicationTransactionTemplate();
 
-    try {
     $comment = $xaction->getApplicationTransactionCommentObject();
     if (!$comment) {
       return 'none';
     }
-    } catch (Exception $ex) {
-      return 'none';
-    }
 
     $comment_row = queryfx_one(
       $comment->establishConnection('r'),

src/applications/search/storage/PhabricatorProfileMenuItemConfigurationTransaction.php

@@ -20,8 +20,4 @@ final class PhabricatorProfileMenuItemConfigurationTransaction
     return PhabricatorProfileMenuItemPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
 }

src/applications/settings/storage/PhabricatorUserPreferencesTransaction.php

@@ -11,10 +11,6 @@ final class PhabricatorUserPreferencesTransaction
     return 'user';
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getApplicationTransactionType() {
     return PhabricatorUserPreferencesPHIDType::TYPECONST;
   }

src/applications/spaces/storage/PhabricatorSpacesNamespaceTransaction.php

@@ -11,10 +11,6 @@ final class PhabricatorSpacesNamespaceTransaction
     return PhabricatorSpacesNamespacePHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getBaseTransactionClass() {
     return 'PhabricatorSpacesNamespaceTransactionType';
   }

src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php

@@ -360,12 +360,7 @@ abstract class PhabricatorApplicationTransactionEditor
     }
 
     if ($template) {
-      try {
       $comment = $template->getApplicationTransactionCommentObject();
-      } catch (PhutilMethodNotImplementedException $ex) {
-        $comment = null;
-      }
-
       if ($comment) {
         $types[] = PhabricatorTransactions::TYPE_COMMENT;
       }

src/applications/transactions/engineextension/PhabricatorCommentEditEngineExtension.php

@@ -23,12 +23,7 @@ final class PhabricatorCommentEditEngineExtension
     PhabricatorApplicationTransactionInterface $object) {
 
     $xaction = $object->getApplicationTransactionTemplate();
-
-    try {
     $comment = $xaction->getApplicationTransactionCommentObject();
-    } catch (PhutilMethodNotImplementedException $ex) {
-      $comment = null;
-    }
 
     return (bool)$comment;
   }

src/applications/transactions/storage/PhabricatorApplicationTransaction.php

@@ -76,7 +76,7 @@ abstract class PhabricatorApplicationTransaction
   }
 
   public function getApplicationTransactionCommentObject() {
-    throw new PhutilMethodNotImplementedException();
+    return null;
   }
 
   public function getMetadataValue($key, $default = null) {
@@ -1731,12 +1731,7 @@ abstract class PhabricatorApplicationTransaction
     PhabricatorDestructionEngine $engine) {
 
     $this->openTransaction();
-      $comment_template = null;
-      try {
       $comment_template = $this->getApplicationTransactionCommentObject();
-      } catch (Exception $ex) {
-        // Continue; no comments for these transactions.
-      }
 
       if ($comment_template) {
         $comments = $comment_template->loadAllWhere(

src/applications/transactions/storage/PhabricatorEditEngineConfigurationTransaction.php

@@ -23,10 +23,6 @@ final class PhabricatorEditEngineConfigurationTransaction
     return PhabricatorEditEngineConfigurationPHIDType::TYPECONST;
   }
 
-  public function getApplicationTransactionCommentObject() {
-    return null;
-  }
-
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();