Review of 1.0.3: names a snapshot cannot hold, restore-directory errors under salvage, browse speed

- Leave out and report a file or folder whose name a snapshot cannot hold
- A staging write failure stops a full restore under --salvage
- Browse reuses its repository; empty folders read along with the entries
- Keep leases alive while empty folders are created; exact-prefix empty folder is the target
- Clean up tables that were partly created or before the transaction started
- Bin: no empty message after a read error; longer pages

lib/Db/DbDumper.php

@@ -160,8 +160,8 @@ final class DbDumper {
 		try {
 			foreach ($missing as $table) {
 				if (isset($manifest['tables'][$table]['schema'])) {
+					$report['created'][] = $table; // first: creating it can stop halfway (its indexes)
 					$this->db->createSchemaManager()->createTable(self::tableFromStructure($table, $manifest['tables'][$table]['schema'], $this->tableOptions()));
-					$report['created'][] = $table;
 				} else {
 					$report['missing'][] = $table;
 				}
@@ -172,7 +172,12 @@ final class DbDumper {
 		}
 		$total = 0;
 		$foreignKeys = [];
-		$this->db->beginTransaction();
+		try {
+			$this->db->beginTransaction();
+		} catch (\Throwable $e) {
+			$this->dropCreatedTables($report);
+			throw $e;
+		}
 		try {
 			$foreignKeys = $this->suspendForeignKeys(); // first: on SQLite it also takes the write lock
 			foreach ($manifest['tables'] as $table => $info) {