Merge pull request #25862 from brave/ios-search-engine-crash

[iOS] Fix potential crash when launching the app from a shortcuts widget

ios/brave-ios/Sources/Brave/Frontend/Browser/BrowserViewController/BrowserViewController.swift

@@ -3414,7 +3414,14 @@ extension BrowserViewController {
     }
 
     executeAfterSetup {
-      NavigationPath.handle(nav: path, with: self)
+      Task { @MainActor in
+        if self.profile.searchEngines.orderedEngines.isEmpty {
+          // Wait until search engines are ready
+          await self.profile.searchEngines.waitForSearchEngines()
+        }
+
+        NavigationPath.handle(nav: path, with: self)
+      }
     }
   }
 

ios/brave-ios/Sources/Brave/Frontend/Browser/Search/SearchEngines.swift

@@ -74,16 +74,33 @@ public class SearchEngines {
     setInitialDefaultEngine(engine.legacyName ?? engine.rawValue)
   }
 
+  private var loadingStream: AsyncStream<Void>?
+
   public func loadSearchEngines() async {
+    let loading = AsyncStream<Void>.makeStream()
+    loadingStream = loading.stream
+
     await loadCustomEngines()
     orderedEngines = await getOrderedEngines()
+    loading.continuation.yield()
 
     recordSearchEngineP3A()
     if let defaultEngine = defaultEngine(forType: .standard) {
       recordSearchEngineChangedP3A(from: defaultEngine)
     }
   }
 
+  /// Waits until a previous call to `loadSearchEngines` completes
+  public func waitForSearchEngines() async {
+    if !orderedEngines.isEmpty {
+      return
+    }
+    guard let loadingStream else { return }
+    for await _ in loadingStream {
+      return
+    }
+  }
+
   /// If no engine type is specified this method returns search engine for regular browsing.
   func defaultEngine(forType engineType: DefaultEngineType) -> OpenSearchEngine? {
     if let name = engineType.option.value,
@@ -97,7 +114,7 @@ public class SearchEngines {
     let defaultEngineName = initialSearchEngines.defaultSearchEngine.rawValue
 
     let defaultEngine = orderedEngines.first(where: { $0.engineID == defaultEngineName })
-    return defaultEngine ?? orderedEngines[0]
+    return defaultEngine ?? orderedEngines.first
   }
 
   /// Initialize default engine and set order of remaining search engines.