restore NSPersistentStore.affectedStores ARC bug workaround

Sources/CoreStoreFetchRequest.swift

@@ -0,0 +1,91 @@
+//
+//  CoreStoreFetchRequest.swift
+//  CoreStore
+//
+//  Copyright © 2019 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+import ObjectiveC
+
+
+// MARK: - CoreStoreFetchRequest
+
+// Bugfix for NSFetchRequest messing up memory management for `affectedStores`
+// http://stackoverflow.com/questions/14396375/nsfetchedresultscontroller-crashes-in-ios-6-if-affectedstores-is-specified
+internal final class CoreStoreFetchRequest<T: NSFetchRequestResult>: NSFetchRequest<NSFetchRequestResult> {
+
+    @nonobjc
+    internal func safeAffectedStores() -> [NSPersistentStore]? {
+
+        return self.copiedAffectedStores as! [NSPersistentStore]?
+    }
+
+    @nonobjc @inline(__always)
+    internal func staticCast() -> NSFetchRequest<T> {
+
+        return unsafeBitCast(self, to: NSFetchRequest<T>.self)
+    }
+
+    @nonobjc @inline(__always)
+    internal func dynamicCast<U>() -> NSFetchRequest<U> {
+
+        return unsafeBitCast(self, to: NSFetchRequest<U>.self)
+    }
+
+
+    // MARK: NSFetchRequest
+
+    @objc dynamic
+    override var affectedStores: [NSPersistentStore]? {
+
+        get {
+
+            return super.affectedStores
+        }
+        set {
+
+            if #available(iOS 11.0, macOS 10.13, watchOS 4.0, tvOS 11.0) {
+
+                self.copiedAffectedStores = (newValue as NSArray?)?.copy() as! NSArray?
+                super.affectedStores = newValue
+                return
+            }
+            // Bugfix for NSFetchRequest messing up memory management for `affectedStores`
+            // http://stackoverflow.com/questions/14396375/nsfetchedresultscontroller-crashes-in-ios-6-if-affectedstores-is-specified
+            if let releaseArray = self.releaseArray {
+
+                releaseArray.release()
+                self.releaseArray = nil
+            }
+            self.copiedAffectedStores = (newValue as NSArray?)?.copy() as! NSArray?
+            super.affectedStores = newValue
+            self.releaseArray = (super.affectedStores as NSArray?).map(Unmanaged<NSArray>.passRetained(_:))
+        }
+    }
+
+
+    // MARK: Private
+
+    private var copiedAffectedStores: NSArray?
+    private var releaseArray: Unmanaged<NSArray>?
+}