Define RevisionRecord::isCurrent

Currently only RevisionStoreRecord::isCurrent exists,
and it is the only implementation where the method makes
sence. However, checking with instanceof prior to calling
it for every RevisionRecord is inconvenient. This patch pulls
the method up into RevisionRecord with default implementation
returning false.

Change-Id: I89852ca210b29825ce8fc9e13610e892c650ba14

includes/Revision/RevisionRecord.php

@@ -574,6 +574,15 @@ abstract class RevisionRecord {
 			&& $this->mSlots->getSlotRoles() !== [];
 	}
 
+	/**
+	 * Checks whether the revision record is a stored current revision.
+	 * @since 1.35
+	 * @return bool
+	 */
+	public function isCurrent() {
+		return false;
+	}
+
 }
 
 /**

includes/Revision/RevisionStoreRecord.php

@@ -105,9 +105,7 @@ class RevisionStoreRecord extends RevisionRecord {
 	}
 
 	/**
-	 * MCR migration note: this replaces Revision::isCurrent
+	 * @inheritDoc
-	 *
-	 * @return bool
 	 */
 	public function isCurrent() {
 		return $this->mCurrent;

tests/phpunit/includes/Revision/MutableRevisionRecordTest.php

@@ -349,4 +349,13 @@ class MutableRevisionRecordTest extends MediaWikiTestCase {
 	public function testNotReadyForInsertion( $rev ) {
 		$this->assertFalse( $rev->isReadyForInsertion() );
 	}
+
+	/**
+	 * @covers \MediaWiki\Revision\RevisionRecord::isCurrent
+	 */
+	public function testIsCurrent() {
+		$rev = new MutableRevisionRecord( Title::newFromText( 'Foo' ) );
+		$this->assertFalse( $rev->isCurrent(),
+			MutableRevisionRecord::class . ' cannot be stored current revision' );
+	}
 }

tests/phpunit/includes/Revision/RevisionArchiveRecordTest.php

@@ -269,4 +269,12 @@ class RevisionArchiveRecordTest extends MediaWikiTestCase {
 		new RevisionArchiveRecord( $title, $user, $comment, $row, $slots, $wikiId );
 	}
 
+	/**
+	 * @covers \MediaWiki\Revision\RevisionRecord::isCurrent
+	 */
+	public function testIsCurrent() {
+		$rev = $this->newRevision();
+		$this->assertFalse( $rev->isCurrent(),
+			RevisionArchiveRecord::class . ' cannot be stored current revision' );
+	}
 }