fix: release rolled-back savepoints

Author: ShiroKSH

Sources/SQLite/Core/Connection.swift

@@ -429,17 +429,27 @@ public final class Connection {
         let name = name.quote("'")
         let savepoint = "SAVEPOINT \(name)"
 
-        try transaction(savepoint, block, "RELEASE \(savepoint)", or: "ROLLBACK TO \(savepoint)")
+        try transaction(
+            savepoint,
+            block,
+            "RELEASE \(savepoint)",
+            or: "ROLLBACK TO \(savepoint)",
+            followedBy: "RELEASE \(savepoint)"
+        )
     }
 
-    fileprivate func transaction(_ begin: String, _ block: () throws -> Void, _ commit: String, or rollback: String) throws {
+    fileprivate func transaction(_ begin: String, _ block: () throws -> Void, _ commit: String,
+                                 or rollback: String, followedBy cleanup: String? = nil) throws {
         return try sync {
             try self.run(begin)
             do {
                 try block()
                 try self.run(commit)
             } catch {
                 try self.run(rollback)
+                if let cleanup {
+                    try self.run(cleanup)
+                }
                 throw error
             }
         }

Tests/SQLiteTests/Core/ConnectionTests.swift

@@ -315,8 +315,27 @@ class ConnectionTests: SQLiteTestCase {
         assertSQL("INSERT INTO users (email) VALUES ('alice@example.com')", 2)
         assertSQL("ROLLBACK TO SAVEPOINT '2'")
         assertSQL("ROLLBACK TO SAVEPOINT '1'")
-        assertSQL("RELEASE SAVEPOINT '2'", 0)
-        assertSQL("RELEASE SAVEPOINT '1'", 0)
+        assertSQL("RELEASE SAVEPOINT '2'")
+        assertSQL("RELEASE SAVEPOINT '1'")
+    }
+
+    func test_savepoint_releasesAfterRollback() throws {
+        let rollbackError = NSError(domain: "com.stephencelis.SQLiteTests", code: 1, userInfo: nil)
+
+        XCTAssertThrowsError(try db.savepoint("1") {
+            try db.run("INSERT INTO users (email) VALUES (?)", "alice@example.com")
+            throw rollbackError
+        }) { error in
+            let error = error as NSError
+            XCTAssertEqual(rollbackError.domain, error.domain)
+            XCTAssertEqual(rollbackError.code, error.code)
+        }
+
+        XCTAssertEqual(0, try db.scalar(users.count))
+        try db.transaction {
+            try db.run("INSERT INTO users (email) VALUES (?)", "alice@example.com")
+        }
+        XCTAssertEqual(1, try db.scalar(users.count))
     }
 
     func test_updateHook_setsUpdateHook_withInsert() throws {