Fix sad panda check

app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt

@@ -124,7 +124,7 @@ private fun rethrowExactly(response: HttpResponse, body: Either<String, ByteBuff
         { !it.hasRemaining() },
     )
     if (empty) {
-        val message = if (EhUtils.isExHentai) {
+        val message = if (response.request.url.host == EhUrl.DOMAIN_EX) {
             "Sad Panda\n(without panda)"
         } else {
             appCtx.getString(R.string.error_ip_banned)

app/src/main/kotlin/com/hippo/ehviewer/ui/login/WebViewSignInScreen.kt

@@ -31,6 +31,7 @@ fun AnimatedVisibilityScope.WebViewSignInScreen(navigator: DestinationsNavigator
                     Settings.desktopSite.value = false
                 }
                 if (EhCookieStore.hasSignedIn()) {
+                    EhCookieStore.flush()
                     postLogin()
                     state.webView?.destroy()
                     bgWork { awaitCancellation() }

app/src/main/rust/src/ffi/jvm.rs

@@ -256,6 +256,7 @@ where
     R: Serialize,
 {
     jni_throwing(env, |env| {
+        ensure!(limit > 0, "Empty response");
         let buffer = deref_mut_direct_bytebuffer(env, str)?;
 
         // SAFETY: ktor client ensure html content is valid utf-8.