From cfea3aba34a45fa4159022e5327f514415525158 Mon Sep 17 00:00:00 2001
From: "Calum H." <calum@modrinth.com>
Date: Tue, 4 Aug 2026 15:29:03 +0100
Subject: [PATCH] fix: mc account logout on stale (#6986)

---
 apps/app-frontend/src/pages/Skins.vue        |  1 +
 packages/app-lib/src/api/minecraft_auth.rs   |  2 +-
 packages/app-lib/src/state/minecraft_auth.rs | 37 ++++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/apps/app-frontend/src/pages/Skins.vue b/apps/app-frontend/src/pages/Skins.vue
index 6c89f34712..f6a9282bf6 100644
--- a/apps/app-frontend/src/pages/Skins.vue
+++ b/apps/app-frontend/src/pages/Skins.vue
@@ -1038,6 +1038,7 @@ async function checkUserChanges() {
 	try {
 		const defaultId = await get_default_user()
 		if (defaultId !== currentUserId.value) {
+			await accountsCard.value?.refreshValues()
 			await loadCurrentUser()
 			await loadCapes()
 			await loadSkins()
diff --git a/packages/app-lib/src/api/minecraft_auth.rs b/packages/app-lib/src/api/minecraft_auth.rs
index 931b8e75bb..a347d24d68 100644
--- a/packages/app-lib/src/api/minecraft_auth.rs
+++ b/packages/app-lib/src/api/minecraft_auth.rs
@@ -39,7 +39,7 @@ pub async fn finish_login(
 #[tracing::instrument]
 pub async fn get_default_user() -> crate::Result<Option<uuid::Uuid>> {
     let state = State::get().await?;
-    let user = Credentials::get_active(&state.pool).await?;
+    let user = Credentials::get_default_credential(&state.pool).await?;
     Ok(user.map(|user| user.offline_profile.id))
 }
 
diff --git a/packages/app-lib/src/state/minecraft_auth.rs b/packages/app-lib/src/state/minecraft_auth.rs
index c021a239d2..b835ad439d 100644
--- a/packages/app-lib/src/state/minecraft_auth.rs
+++ b/packages/app-lib/src/state/minecraft_auth.rs
@@ -79,6 +79,26 @@ pub enum MinecraftAuthenticationError {
     NoUserHash,
 }
 
+#[derive(Deserialize)]
+struct OAuthErrorResponse {
+    error: String,
+}
+
+impl MinecraftAuthenticationError {
+    fn is_invalid_grant(&self) -> bool {
+        matches!(
+            self,
+            Self::DeserializeResponse {
+                step: MinecraftAuthStep::RefreshOAuthToken,
+                raw,
+                status_code: StatusCode::BAD_REQUEST,
+                ..
+            } if serde_json::from_str::<OAuthErrorResponse>(raw)
+                .is_ok_and(|response| response.error == "invalid_grant")
+        )
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct MinecraftLoginFlow {
     pub verifier: String,
@@ -466,6 +486,23 @@ impl Credentials {
                         return Ok(Some(creds));
                     }
 
+                    if matches!(
+                        &*err.raw,
+                        ErrorKind::MinecraftAuthenticationError(source)
+                            if source.is_invalid_grant()
+                    ) {
+                        Self::remove(creds.offline_profile.id, exec).await?;
+
+                        if let Some((_, mut user)) =
+                            Self::get_all(exec).await?.into_iter().next()
+                        {
+                            user.active = true;
+                            user.upsert(exec).await?;
+                        }
+
+                        return Ok(None);
+                    }
+
                     Err(err)
                 }
             }