[Settings]: Fix: DisableAppLimit switch reverting back to off state even if on iOS where sparseRestore is not patched yet

AltStoreCore/Extensions/ProcessInfo+AltStore.swift

@@ -0,0 +1,96 @@
+//
+//  ProcessInfo+SideStore.swift
+//  SideStore
+//
+//  Created by ny on 10/23/24.
+//  Copyright © 2024 SideStore. All rights reserved.
+//
+
+import Foundation
+
+fileprivate struct BuildVersion: Comparable {
+    let prefix: String
+    let numericPart: Int
+    let suffix: Character?
+    
+    init?(_ buildString: String) {
+        // Initialize indices
+        var index = buildString.startIndex
+        
+        // Extract prefix (letters before the numeric part)
+        while index < buildString.endIndex, !buildString[index].isNumber {
+            index = buildString.index(after: index)
+        }
+        guard index > buildString.startIndex else { return nil }
+        self.prefix = String(buildString[buildString.startIndex..<index])
+        
+        // Extract numeric part
+        let startOfNumeric = index
+        while index < buildString.endIndex, buildString[index].isNumber {
+            index = buildString.index(after: index)
+        }
+        guard let numericValue = Int(buildString[startOfNumeric..<index]) else { return nil }
+        self.numericPart = numericValue
+        
+        // Extract suffix (if any)
+        if index < buildString.endIndex {
+            self.suffix = buildString[index]
+        } else {
+            self.suffix = nil
+        }
+    }
+    
+    // Implement Comparable protocol
+    static func < (lhs: BuildVersion, rhs: BuildVersion) -> Bool {
+        // Compare prefixes
+        if lhs.prefix != rhs.prefix {
+            return lhs.prefix < rhs.prefix
+        }
+        // Compare numeric parts
+        if lhs.numericPart != rhs.numericPart {
+            return lhs.numericPart < rhs.numericPart
+        }
+        // Compare suffixes
+        switch (lhs.suffix, rhs.suffix) {
+        case let (l?, r?):
+            return l < r
+        case (nil, _?):
+            return true // nil is considered less than any character
+        case (_?, nil):
+            return false
+        default:
+            return false // Both are nil and equal
+        }
+    }
+    
+    static func == (lhs: BuildVersion, rhs: BuildVersion) -> Bool {
+        return lhs.prefix == rhs.prefix &&
+        lhs.numericPart == rhs.numericPart &&
+        lhs.suffix == rhs.suffix
+    }
+}
+
+extension ProcessInfo {
+    public var shortVersion: String {
+        operatingSystemVersionString
+            .replacingOccurrences(of: "Version ", with: "")
+            .replacingOccurrences(of: "Build ", with: "")
+    }
+    
+    public var operatingSystemBuild: String {
+        if let start = shortVersion.range(of: "(")?.upperBound,
+           let end = shortVersion.range(of: ")")?.lowerBound {
+            shortVersion[start..<end].replacingOccurrences(of: "Build ", with: "")
+        } else { "???" }
+    }
+    
+    public var sparseRestorePatched: Bool {
+        if operatingSystemVersion < OperatingSystemVersion(majorVersion: 18, minorVersion: 1, patchVersion: 0) { false }
+        else if operatingSystemVersion > OperatingSystemVersion(majorVersion: 18, minorVersion: 1, patchVersion: 1) { true }
+        else if operatingSystemVersion >= OperatingSystemVersion(majorVersion: 18, minorVersion: 1, patchVersion: 0),
+                let currentBuild = BuildVersion(operatingSystemBuild),
+                let targetBuild  = BuildVersion("22B5054e") {
+            currentBuild >= targetBuild
+        } else { false }
+    }
+}

AltStoreCore/Extensions/UserDefaults+AltStore.swift

@@ -143,7 +143,8 @@ public extension UserDefaults
         UserDefaults.standard.register(defaults: defaults)
         UserDefaults.shared.register(defaults: defaults)
         
-        if !isMacDirtyCowSupported
+        // MDC is unsupported and spareRestore is patched
+        if !isMacDirtyCowSupported && ProcessInfo().sparseRestorePatched
         {
             // Disable isAppLimitDisabled if running iOS version that doesn't support MacDirtyCow.
             UserDefaults.standard.isAppLimitDisabled = false