Check replicas are there, when meta_p.wiki says so

src/Model/Project.php

@@ -107,7 +107,8 @@ protected function getMetadata(): ?array {
 	 * @return bool
 	 */
 	public function exists(): bool {
-		return !empty( $this->getDomain() );
+		return !empty( $this->getDomain() )
+			&& $this->repository->checkReplication($this->getBasicInfo()['dbName']);
 	}
 
 	/**
@@ -148,9 +149,9 @@ public function getUrl( bool $withTrailingSlash = true ): string {
 	/**
 	 * @param Page|string $page Full page title including namespace, or a Page object.
 	 * @param bool $useUnnormalizedPageTitle Use the unnormalized page title to avoid
-	 *    an API call. This should be used only if you fetched the page title via other
-	 *    means (SQL query), and is not from user input alone. Only applicable if $page
-	 *    is a Page object.
+	 *	  an API call. This should be used only if you fetched the page title via other
+	 *	  means (SQL query), and is not from user input alone. Only applicable if $page
+	 *	  is a Page object.
 	 * @return string
 	 */
 	public function getUrlForPage( Page|string $page, bool $useUnnormalizedPageTitle = false ): string {
@@ -356,5 +357,5 @@ public function userHasOptedIn( User $user ): bool {
 	 */
 	public function getTableName( string $tableName, ?string $tableExtension = null ): string {
 		return $this->getRepository()->getTableName( $this->getDatabaseName(), $tableName, $tableExtension );
-	}
+  }
 }

src/Repository/GlobalContribsRepository.php

@@ -55,6 +55,8 @@ public function globalEditCounts( User $user ): ?array {
 
 		// Pre-populate all projects' metadata, to prevent each project call from fetching it.
 		$this->caProject->getRepository()->getAll();
+
+		$this->checkReplicationAllProjects();
 
 		// Compile the output.
 		$out = [];
@@ -110,6 +112,34 @@ protected function globalEditCountsFromCentralAuth( User $user ): ?array {
 		// Cache and return.
 		return $this->setCache( $cacheKey, $out );
 	}
+
+	/**
+	 * Get, slice by slice, the list of projects that are actually replicated.
+	 * Takes about 0.5s per slice.
+	 * @return bool[] Keyed by database name, all values are true.
+	 */
+	public function checkReplicationAllProjects(): array {
+		$cacheKey = $this->getCacheKey( "global_replication_check" );
+		if ( $this->cache->hasItem( $cacheKey ) ) {
+			return $this->cache->getItem( $cacheKey )->get();
+		}
+		$result = [];
+		$exists = true;
+		$i = 0;
+		$sql = "SELECT DISTINCT table_schema
+				FROM information_schema.tables";
+		while ( $exists ) {
+			$i += 1;
+			try {
+				$queryResult = $this->executeProjectsQuery( "s$i", $sql )->fetchFirstColumn();
+				$result = array_merge( $result, $queryResult );
+			} catch ( \Throwable ) {
+				$exists = false;
+			}
+		}
+		return $this->setCache( $cacheKey, $result, 'PT1H' );
+	}
+
 
 	/**
 	 * Loop through the given dbNames and create Project objects for each.

src/Repository/ProjectRepository.php

@@ -219,7 +219,47 @@ public function getOne( string $project ): ?array {
 		// Cache for one hour and return.
 		return $this->setCache( $cacheKey, $basicInfo, 'PT1H' );
 	}
-
+
+	/**
+	 * Is this project actually replicated? Sometimes projets aren't,
+	 * despite being listed in meta_p.wiki. See T322466.
+	 * @param string $project Database name, without _p.
+	 * @return bool
+	 */
+	public function checkReplication( string $project ): bool {
+		if ( '' == $project ) {
+			// This means we failed to getBasicInfo. Let's try and AGF.
+			// Plus, keeps tests from breaking down.
+			return true;
+		}
+		$cacheKey = $this->getCacheKey( $project, "replication_check" );
+		if ( $this->cache->hasItem( $cacheKey )) {
+			return $this->cache->getItem( $cacheKey )->get();
+		}
+		// GlobalContribs preloads replication checks for *all* projects
+		$allProjectsCacheKey = $this->getCacheKey( '', "global_replication_check" );
+		if ( $this->cache->hasItem( $allProjectsCacheKey )) {
+			$globalReplicationChecks = $this->cache->getItem( $allProjectsCacheKey )->get();
+			return array_key_exists( $project, $globalReplicationChecks );
+		}
+		$dbList = $this->getDbList();
+		if ( !array_key_exists( $project, $dbList )) {
+			$result = false;
+		} else {
+			$dbSlice = $dbList[$project];
+			$sql = "SELECT 1
+					FROM information_schema.tables
+					WHERE table_schema = :project
+					LIMIT 1";
+			$queryResult = $this->executeProjectsQuery( $dbSlice, $sql, [
+				'project' => $project . "_p",
+			] )->fetchAssociative();
+			$result = ( 1 == count( $queryResult ));
+		}
+		// Cache for 1h and return
+		return $this->setCache( $cacheKey, $result, 'PT1H' ); // feels long to me, but as long as getOne
+	}
+
 	/**
 	 * Get metadata about a project, including the 'dbName', 'url' and 'lang'
 	 *

tests/Model/GlobalContribsTest.php

@@ -86,6 +86,8 @@ public function testGlobalEdits(): void {
 				'dbName' => 'wiki1',
 				'url' => 'https://wiki1.example.org',
 			] );
+    $wiki1Repo->method('checkReplication')
+      ->willReturn(true);
 		$wiki1 = new Project( 'wiki1' );
 		$wiki1->setRepository( $wiki1Repo );
 

tests/TestAdapter.php

@@ -30,6 +30,8 @@ public function getProjectRepo(): MockObject {
 				'dbName' => 'test_wiki',
 				'lang' => 'en',
 			] );
+		$repo->method('checkReplication')
+			->willReturn(true);
 		return $repo;
 	}