perf(users): drop redundant get_user_by_id refetch in session-user endpoints (#23794)

* perf(users): drop redundant get_user_by_id refetch in session-user endpoints

Five /user/* handlers refetched the user row via Users.get_user_by_id(user.id)
immediately after receiving an identical UserModel from Depends(get_verified_user).
Since get_verified_user already populated the user within the same request
microseconds earlier, the refetch is pure overhead. The dead else branches
(unreachable — get_verified_user raises 401 on missing user) are removed as
a natural consequence.

Affected endpoints:
- GET  /user/settings
- GET  /user/status
- POST /user/status/update
- GET  /user/info
- POST /user/info/update

Eliminates one SELECT per request to each of these endpoints with no behavioral
change.

* fix(users): preserve USER_NOT_FOUND error on status update failure

update_user_status_by_id returns None when the target user is missing or
the update raises. The previous commit removed the pre-update existence
gate (get_user_by_id) and returned the update result directly, which
turned not-found/failure cases into 200 OK with a null body instead of
the expected 400 USER_NOT_FOUND.

Guard the update result explicitly to preserve the original API contract,
matching the equivalent pattern already applied in /user/info/update.

* docs(users): note lost-update tradeoff on /user/info/update

Make the concurrency tradeoff explicit: merging against the auth-time
snapshot slightly widens the lost-update window compared to the previous
pre-merge refetch, but the refetch only narrowed (did not eliminate) that
window. Real safety requires row locking or a version column.

---------

Co-authored-by: Claude <noreply@anthropic.com>

backend/open_webui/routers/users.py

@@ -276,14 +276,8 @@ async def update_default_user_permissions(request: Request, form_data: UserPermi
 async def get_user_settings_by_session_user(
     user=Depends(get_verified_user), db: AsyncSession = Depends(get_async_session)
 ):
-    user = await Users.get_user_by_id(user.id, db=db)
-    if user:
-        return user.settings
-    else:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=ERROR_MESSAGES.USER_NOT_FOUND,
-        )
+    # user already fetched by get_verified_user — no need to refetch
+    return user.settings
 
 
 ############################
@@ -339,14 +333,8 @@ async def get_user_status_by_session_user(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=ERROR_MESSAGES.ACTION_PROHIBITED,
         )
-    user = await Users.get_user_by_id(user.id, db=db)
-    if user:
-        return user
-    else:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=ERROR_MESSAGES.USER_NOT_FOUND,
-        )
+    # user already fetched by get_verified_user — no need to refetch
+    return user
 
 
 ############################
@@ -366,15 +354,14 @@ async def update_user_status_by_session_user(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=ERROR_MESSAGES.ACTION_PROHIBITED,
         )
-    user = await Users.get_user_by_id(user.id, db=db)
-    if user:
-        user = await Users.update_user_status_by_id(user.id, form_data, db=db)
-        return user
-    else:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=ERROR_MESSAGES.USER_NOT_FOUND,
-        )
+    # user already fetched by get_verified_user — no need to refetch
+    updated = await Users.update_user_status_by_id(user.id, form_data, db=db)
+    if updated:
+        return updated
+    raise HTTPException(
+        status_code=status.HTTP_400_BAD_REQUEST,
+        detail=ERROR_MESSAGES.USER_NOT_FOUND,
+    )
 
 
 ############################
@@ -384,14 +371,8 @@ async def update_user_status_by_session_user(
 
 @router.get('/user/info', response_model=Optional[dict])
 async def get_user_info_by_session_user(user=Depends(get_verified_user), db: AsyncSession = Depends(get_async_session)):
-    user = await Users.get_user_by_id(user.id, db=db)
-    if user:
-        return user.info
-    else:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=ERROR_MESSAGES.USER_NOT_FOUND,
-        )
+    # user already fetched by get_verified_user — no need to refetch
+    return user.info
 
 
 ############################
@@ -403,19 +384,13 @@ async def get_user_info_by_session_user(user=Depends(get_verified_user), db: Asy
 async def update_user_info_by_session_user(
     form_data: dict, user=Depends(get_verified_user), db: AsyncSession = Depends(get_async_session)
 ):
-    user = await Users.get_user_by_id(user.id, db=db)
-    if user:
-        if user.info is None:
-            user.info = {}
-
-        user = await Users.update_user_by_id(user.id, {'info': {**user.info, **form_data}}, db=db)
-        if user:
-            return user.info
-        else:
-            raise HTTPException(
-                status_code=status.HTTP_400_BAD_REQUEST,
-                detail=ERROR_MESSAGES.USER_NOT_FOUND,
-            )
+    # Merges against the auth-time snapshot of user.info. The previous pre-merge
+    # refetch only narrowed (did not eliminate) the lost-update window on concurrent
+    # same-user writes; real safety needs row locking or a version column.
+    existing_info = user.info or {}
+    updated = await Users.update_user_by_id(user.id, {'info': {**existing_info, **form_data}}, db=db)
+    if updated:
+        return updated.info
     else:
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,