As recommended in the docs, mark custom functions SQLITE_DIRECTONLY b…

…y default (security hardening). Provide an initializer flag to override it if needed.

Sources/SQLiteNIO/SQLiteCustomFunction.swift

@@ -24,10 +24,12 @@ public final class SQLiteCustomFunction: Hashable {
 
     /// The name of the SQL function
     public var name: String { identity.name }
+
     private let identity: Identity
     private let pure: Bool
+    private let indirect: Bool
     private let kind: Kind
-    private var eTextRep: Int32 { (SQLITE_UTF8 | (pure ? SQLITE_DETERMINISTIC : 0)) }
+    private var eTextRep: Int32 { (SQLITE_UTF8 | (pure ? SQLITE_DETERMINISTIC : 0) | (indirect ? 0 : SQLITE_DIRECTONLY)) }
 
     public struct SQLiteCustomFunctionArgumentError: Error {
         public let count: Int
@@ -38,19 +40,19 @@ public final class SQLiteCustomFunction: Hashable {
         _ name: String,
         argumentCount: Int32? = nil,
         pure: Bool = false,
+        indirect: Bool = false,
         function: @Sendable @escaping ([SQLiteData]) throws -> (any SQLiteDataConvertible)?)
     {
         self.identity = Identity(name: name, nArg: argumentCount ?? -1)
         self.pure = pure
+        self.indirect = indirect
         self.kind = .function { (argc, argv) in
-            let count = Int(argc)
-            let arguments = try (0 ..< count).map { index -> SQLiteData in
+            try function((0 ..< Int(argc)).map { index -> SQLiteData in
                 guard let value = argv?[index] else {
-                    throw SQLiteCustomFunctionArgumentError(count: count, index: index)
+                    throw SQLiteCustomFunctionArgumentError(count: Int(argc), index: index)
                 }
                 return try SQLiteData(sqliteValue: value)
-            }
-            return try function(arguments)
+            })
         }
     }
 
@@ -95,33 +97,30 @@ public final class SQLiteCustomFunction: Hashable {
         _ name: String,
         argumentCount: Int32? = nil,
         pure: Bool = false,
+        indirect: Bool = false,
         aggregate: Aggregate.Type
     ) {
         self.identity = Identity(name: name, nArg: argumentCount ?? -1)
         self.pure = pure
+        self.indirect = indirect
         self.kind = .aggregate { Aggregate() }
     }
 
     /// Invokes `sqlite3_create_function_v2()` to install a custom function.
     /// See https://sqlite.org/c3ref/create_function.html
     func install(in connection: SQLiteConnection) throws {
         // Retain the function definition
-        let definition = kind.definition
-        let definitionP = Unmanaged.passRetained(definition).toOpaque()
-
         let code = sqlite_nio_sqlite3_create_function_v2(
             connection.handle.raw,
-            identity.name,
-            identity.nArg,
-            eTextRep,
-            definitionP,
-            kind.xFunc,
-            kind.xStep,
-            kind.xFinal,
-            { definitionP in
-                // Release the function definition
-                Unmanaged<AnyObject>.fromOpaque(definitionP!).release()
-            })
+            self.identity.name,
+            self.identity.nArg,
+            self.eTextRep,
+            Unmanaged.passRetained(self.kind.definition).toOpaque(),
+            self.kind.xFunc,
+            self.kind.xStep,
+            self.kind.xFinal,
+            { Unmanaged<AnyObject>.fromOpaque($0!).release() } // Release the function definition
+        )
 
         guard code == SQLITE_OK else {
             throw SQLiteError(statusCode: code, connection: connection)
@@ -133,10 +132,11 @@ public final class SQLiteCustomFunction: Hashable {
     func uninstall(in connection: SQLiteConnection) throws {
         let code = sqlite_nio_sqlite3_create_function_v2(
             connection.handle.raw,
-            identity.name,
-            identity.nArg,
-            eTextRep,
-            nil, nil, nil, nil, nil)
+            self.identity.name,
+            self.identity.nArg,
+            self.eTextRep,
+            nil, nil, nil, nil, nil
+        )
 
         guard code == SQLITE_OK else {
             throw SQLiteError(statusCode: code, connection: connection)