修复 iOS 15 下 WKWebView 的 NavigationDelegate 的 block 写入签名崩溃的问题

OCRunner/RunEnv/MFBlock.m

@@ -81,6 +81,20 @@ BOOL NSBlockHasSignature(id block){
 }
 void NSBlockSetSignature(id block, const char *typeencode){
     struct MFSimulateBlock *blockRef = (__bridge struct MFSimulateBlock *)block;
+    // ---- 2021.9.24 TODO:
+    // 针对 WKWebView 的 navigationDelegate 的 block:
+    // decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
+    // ios 15 下直接写入 signatureLocation 内存会导致 EXC_BAD_ACCESS 错误，同时此 block 是一个堆 block，使用内存地址直接写入按理说应该是没有问题。不知是对此内存做了内存保护🤔？可是当在调试的时候，使用 lldb 调试器写入该地址，却完全没有问题。
+    // 目前为了规避崩溃问题，既然不能操作 signature 的地址内存，那就直接覆盖 descriptor 的内存
+    // ⚠️ 此处存在的问题为：使用 malloc 开辟的内存空间，存在内存泄漏的问题。
+    struct MFGOSimulateBlockDescriptor *des = malloc(sizeof(struct MFGOSimulateBlockDescriptor));
+    memcpy(des, blockRef->descriptor, sizeof(struct MFGOSimulateBlockDescriptor));
+    // 直接 free 原本的 descriptor 的内存会崩溃
+//    void *before = blockRef->descriptor;
+    blockRef->descriptor = des;
+//    free(before);
+    // ----
+
     void *signatureLocation = blockRef->descriptor;
     signatureLocation += sizeof(unsigned long int);
     signatureLocation += sizeof(unsigned long int);

OCRunnerDemo/OCRunnerDemo/HotPath/ViewController1.m

@@ -8,6 +8,11 @@
 
 #import "ViewController.h"
 #import <Masonry/Masonry.h>
+typedef NS_ENUM(NSInteger, WKNavigationActionPolicy) {
+    WKNavigationActionPolicyCancel,
+    WKNavigationActionPolicyAllow,
+    WKNavigationActionPolicyDownload
+};
 void cfunctionCallBlock(void (^block)(NSString *)){
     if (block) block(@"cfunctionCallBlock");
 }
@@ -95,6 +100,10 @@ - (void)viewDidLoad {
     [self receiveStackBlock:^(NSString *str){ NSLog(@"%@",str); }];
     cfunctionCallBlock(nil);
     cfunctionCallBlock(^(NSString *str){ NSLog(@"%@",str); });
+    [self ORGviewDidLoad];
+}
+- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
+    decisionHandler(WKNavigationActionPolicyAllow);
 }
 - (void)receiveStackBlock:(void (^)(NSString *))block{
     if (block) block(@"receiveStackBlock:");

OCRunnerDemo/OCRunnerDemo/ViewController.m

@@ -9,6 +9,8 @@
 #import "ViewController.h"
 #import <Masonry/Masonry.h>
 #import <OCRunner/MFBlock.h>
+#import <WebKit/WebKit.h>
+
 @interface ShareInstance: NSObject
 @property (nonatomic,copy)NSDictionary *cache;
 @end
@@ -34,16 +36,27 @@ - (NSString *)cacheForKey:(NSString *)key{
 @end
 
 
-@interface ViewController ()
-
+@interface ViewController () <WKNavigationDelegate>
+@property (nonatomic, strong)WKWebView *webView;
 @end
 
 @implementation ViewController
 
 
 - (void)viewDidLoad {
     [super viewDidLoad];
-
+    WKWebView *webView = [WKWebView new];
+    webView.navigationDelegate = self;
+    [self.view addSubview:webView];
+    [webView mas_makeConstraints:^(MASConstraintMaker *make) {
+        make.width.height.equalTo(@(150));
+        make.right.equalTo(self.view);
+        make.bottom.equalTo(self.view.mas_safeAreaLayoutGuideBottom);
+    }];
+    [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.baidu.com"]]];
+}
+- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
+    decisionHandler(WKNavigationActionPolicyAllow);
 }
 - (void)sendStackBlock{
     __weak typeof(self) weakSelf = self;