Prepare migration from revision_comment_temp to rev_comment_id

This patch introduces a configuration variable that allows one
to control the migration stage in production.

Bug: T299954
Change-Id: I36f1e3cd9fb0f25fd43f4dbb97f791da5eb1147b

2 files changed, 7 insertions, 9 deletions

diff --git a/includes/CommentStore/CommentStore.php b/includes/CommentStore/CommentStore.php
index c47f6e49d435..df21ef797115 100644
--- a/includes/CommentStore/CommentStore.php
+++ b/includes/CommentStore/CommentStore.php
@@ -69,9 +69,14 @@ class CommentStore extends CommentStoreBase {
 	 * @param int $stage One of the MIGRATION_* constants, or an appropriate
 	 *  combination of SCHEMA_COMPAT_* constants. Always MIGRATION_NEW for
 	 *  MediaWiki core since 1.33.
+	 * @param array $tempTableStageOverrides
 	 */
-	public function __construct( Language $lang, $stage ) {
+	public function __construct( Language $lang, $stage, $tempTableStageOverrides ) {
 		parent::__construct( self::TEMP_TABLES, $lang, $stage );
+
+		foreach ( $tempTableStageOverrides as $key => $stageOverride ) {
+			$this->tempTables[$key]['stage'] = $stageOverride;
+		}
 	}
 
 	/**
diff --git a/includes/CommentStore/CommentStoreBase.php b/includes/CommentStore/CommentStoreBase.php
index 4c2e0bde8994..abcdd97ead8d 100644
--- a/includes/CommentStore/CommentStoreBase.php
+++ b/includes/CommentStore/CommentStoreBase.php
@@ -23,7 +23,6 @@ namespace MediaWiki\CommentStore;
 use FormatJson;
 use InvalidArgumentException;
 use Language;
-use LogicException;
 use MediaWiki\Language\RawMessage;
 use Message;
 use OverflowException;
@@ -61,7 +60,7 @@ class CommentStoreBase {
 	 *  - stage: Migration stage
 	 *  - deprecatedIn: Version when using insertWithTempTable() was deprecated
 	 */
-	private $tempTables;
+	protected $tempTables;
 
 	/**
 	 * @var int One of the MIGRATION_* constants, or an appropriate combination
@@ -174,14 +173,8 @@ class CommentStoreBase {
 					if ( ( $tempTableStage & SCHEMA_COMPAT_READ_BOTH ) === SCHEMA_COMPAT_READ_OLD ) {
 						$joinField = "{$alias}.{$t['field']}";
 					} else {
-						// Nothing hits this code path for now, but will in the future when we set
-						// $this->tempTables['rev_comment']['stage'] to MIGRATION_WRITE_NEW while
-						// merging revision_comment_temp into revision.
-						// @codeCoverageIgnoreStart
 						$joins[$alias][0] = 'LEFT JOIN';
 						$joinField = "(CASE WHEN {$key}_id != 0 THEN {$key}_id ELSE {$alias}.{$t['field']} END)";
-						throw new LogicException( 'Nothing should reach this code path at this time' );
-						// @codeCoverageIgnoreEnd
 					}
 				} else {
 					$joinField = "{$key}_id";