[iOS] Gracefully handle errors from -[_SEExtensionProcess makeLibXPCC…

…onnectionError:]

https://bugs.webkit.org/show_bug.cgi?id=267463
rdar://120915929

Reviewed by Per Arne Vollan.

When -makeLibXPCConnectionError: returns nil, log an error and invalidate the extension process
rather than crashing some time later due to a nil m_xpcConnection.

* Source/WebKit/UIProcess/Launcher/cocoa/ProcessLauncherCocoa.mm:
(WebKit::ProcessLauncher::launchProcess):

Canonical link: https://commits.webkit.org/272996@main

Source/WebKit/UIProcess/Launcher/cocoa/ProcessLauncherCocoa.mm

@@ -176,7 +176,17 @@ static void launchWithExtensionKit(ProcessLauncher& processLauncher, ProcessLaun
                 [process invalidate];
                 return;
             }
-            launcher->m_xpcConnection = [process makeLibXPCConnectionError:nil];
+
+            NSError *error = nil;
+            OSObjectPtr xpcConnection = [process makeLibXPCConnectionError:&error];
+            if (!xpcConnection) {
+                RELEASE_LOG_ERROR(Process, "Failed to make libxpc connection for process %{public}@ with error: %{public}@", process.get(), error);
+                [process invalidate];
+                launcher->didFinishLaunchingProcess(0, { });
+                return;
+            }
+
+            launcher->m_xpcConnection = WTFMove(xpcConnection);
             launcher->m_process = WTFMove(process);
             launcher->finishLaunchingProcess(name.characters());
         });