Always assign default language before checking if language is allowed (#5132)

* Always assign default language before checking if language is allowed (fixes #5131)

* handle all logic in same fn

* fix test

* rename

crates/api_crud/src/comment/create.rs

@@ -16,9 +16,8 @@ use lemmy_api_common::{
   },
 };
 use lemmy_db_schema::{
-  impls::actor_language::default_post_language,
+  impls::actor_language::validate_post_language,
   source::{
-    actor_language::CommunityLanguage,
     comment::{Comment, CommentInsertForm, CommentLike, CommentLikeForm},
     comment_reply::{CommentReply, CommentReplyUpdateForm},
     local_site::LocalSite,
@@ -93,21 +92,13 @@ pub async fn create_comment(
     check_comment_depth(parent)?;
   }
 
-  // attempt to set default language if none was provided
-  let language_id = match data.language_id {
-    Some(lid) => lid,
-    None => {
-      default_post_language(
-        &mut context.pool(),
-        community_id,
-        local_user_view.local_user.id,
-      )
-      .await?
-    }
-  };
-
-  CommunityLanguage::is_allowed_community_language(&mut context.pool(), language_id, community_id)
-    .await?;
+  let language_id = validate_post_language(
+    &mut context.pool(),
+    data.language_id,
+    community_id,
+    local_user_view.local_user.id,
+  )
+  .await?;
 
   let comment_form = CommentInsertForm {
     language_id: Some(language_id),

crates/api_crud/src/comment/update.rs

@@ -13,8 +13,8 @@ use lemmy_api_common::{
   },
 };
 use lemmy_db_schema::{
+  impls::actor_language::validate_post_language,
   source::{
-    actor_language::CommunityLanguage,
     comment::{Comment, CommentUpdateForm},
     local_site::LocalSite,
   },
@@ -55,14 +55,13 @@ pub async fn update_comment(
     Err(LemmyErrorType::NoCommentEditAllowed)?
   }
 
-  if let Some(language_id) = data.language_id {
-    CommunityLanguage::is_allowed_community_language(
-      &mut context.pool(),
-      language_id,
-      orig_comment.community.id,
-    )
-    .await?;
-  }
+  let language_id = validate_post_language(
+    &mut context.pool(),
+    data.language_id,
+    orig_comment.community.id,
+    local_user_view.local_user.id,
+  )
+  .await?;
 
   let slur_regex = local_site_to_slur_regex(&local_site);
   let url_blocklist = get_url_blocklist(&context).await?;
@@ -74,7 +73,7 @@ pub async fn update_comment(
   let comment_id = data.comment_id;
   let form = CommentUpdateForm {
     content,
-    language_id: data.language_id,
+    language_id: Some(language_id),
     updated: Some(Some(naive_now())),
     ..Default::default()
   };

crates/api_crud/src/post/create.rs

@@ -17,9 +17,8 @@ use lemmy_api_common::{
   },
 };
 use lemmy_db_schema::{
-  impls::actor_language::default_post_language,
+  impls::actor_language::validate_post_language,
   source::{
-    actor_language::CommunityLanguage,
     community::Community,
     local_site::LocalSite,
     post::{Post, PostInsertForm, PostLike, PostLikeForm},
@@ -98,23 +97,13 @@ pub async fn create_post(
     .await?;
   }
 
-  // attempt to set default language if none was provided
-  let language_id = match data.language_id {
-    Some(lid) => lid,
-    None => {
-      default_post_language(
-        &mut context.pool(),
-        community.id,
-        local_user_view.local_user.id,
-      )
-      .await?
-    }
-  };
-
-  // Only need to check if language is allowed in case user set it explicitly. When using default
-  // language, it already only returns allowed languages.
-  CommunityLanguage::is_allowed_community_language(&mut context.pool(), language_id, community.id)
-    .await?;
+  let language_id = validate_post_language(
+    &mut context.pool(),
+    data.language_id,
+    data.community_id,
+    local_user_view.local_user.id,
+  )
+  .await?;
 
   let scheduled_publish_time =
     convert_published_time(data.scheduled_publish_time, &local_user_view, &context).await?;

crates/api_crud/src/post/update.rs

@@ -15,8 +15,8 @@ use lemmy_api_common::{
   },
 };
 use lemmy_db_schema::{
+  impls::actor_language::validate_post_language,
   source::{
-    actor_language::CommunityLanguage,
     community::Community,
     local_site::LocalSite,
     post::{Post, PostUpdateForm},
@@ -101,14 +101,13 @@ pub async fn update_post(
     Err(LemmyErrorType::NoPostEditAllowed)?
   }
 
-  if let Some(language_id) = data.language_id {
-    CommunityLanguage::is_allowed_community_language(
-      &mut context.pool(),
-      language_id,
-      orig_post.community.id,
-    )
-    .await?;
-  }
+  let language_id = validate_post_language(
+    &mut context.pool(),
+    data.language_id,
+    orig_post.post.community_id,
+    local_user_view.local_user.id,
+  )
+  .await?;
 
   // handle changes to scheduled_publish_time
   let scheduled_publish_time = match (
@@ -131,7 +130,7 @@ pub async fn update_post(
     body,
     alt_text,
     nsfw: data.nsfw,
-    language_id: data.language_id,
+    language_id: Some(language_id),
     updated: Some(Some(naive_now())),
     scheduled_publish_time,
     ..Default::default()

crates/db_schema/src/impls/actor_language.rs

@@ -197,7 +197,7 @@ impl SiteLanguage {
 
 impl CommunityLanguage {
   /// Returns true if the given language is one of configured languages for given community
-  pub async fn is_allowed_community_language(
+  async fn is_allowed_community_language(
     pool: &mut DbPool<'_>,
     for_language_id: LanguageId,
     for_community_id: CommunityId,
@@ -319,29 +319,38 @@ impl CommunityLanguage {
   }
 }
 
-pub async fn default_post_language(
+pub async fn validate_post_language(
   pool: &mut DbPool<'_>,
+  language_id: Option<LanguageId>,
   community_id: CommunityId,
   local_user_id: LocalUserId,
-) -> Result<LanguageId, Error> {
+) -> LemmyResult<LanguageId> {
   use crate::schema::{community_language::dsl as cl, local_user_language::dsl as ul};
   let conn = &mut get_conn(pool).await?;
-  let mut intersection = ul::local_user_language
-    .inner_join(cl::community_language.on(ul::language_id.eq(cl::language_id)))
-    .filter(ul::local_user_id.eq(local_user_id))
-    .filter(cl::community_id.eq(community_id))
-    .select(cl::language_id)
-    .get_results::<LanguageId>(conn)
-    .await?;
+  let language_id = match language_id {
+    None | Some(LanguageId(0)) => {
+      let mut intersection = ul::local_user_language
+        .inner_join(cl::community_language.on(ul::language_id.eq(cl::language_id)))
+        .filter(ul::local_user_id.eq(local_user_id))
+        .filter(cl::community_id.eq(community_id))
+        .select(cl::language_id)
+        .get_results::<LanguageId>(conn)
+        .await?;
 
-  if intersection.len() == 1 {
-    Ok(intersection.pop().unwrap_or(UNDETERMINED_ID))
-  } else if intersection.len() == 2 && intersection.contains(&UNDETERMINED_ID) {
-    intersection.retain(|i| i != &UNDETERMINED_ID);
-    Ok(intersection.pop().unwrap_or(UNDETERMINED_ID))
-  } else {
-    Ok(UNDETERMINED_ID)
-  }
+      if intersection.len() == 1 {
+        intersection.pop().unwrap_or(UNDETERMINED_ID)
+      } else if intersection.len() == 2 && intersection.contains(&UNDETERMINED_ID) {
+        intersection.retain(|i| i != &UNDETERMINED_ID);
+        intersection.pop().unwrap_or(UNDETERMINED_ID)
+      } else {
+        UNDETERMINED_ID
+      }
+    }
+    Some(lid) => lid,
+  };
+
+  CommunityLanguage::is_allowed_community_language(pool, language_id, community_id).await?;
+  Ok(language_id)
 }
 
 /// If no language is given, set all languages
@@ -590,7 +599,7 @@ mod tests {
 
   #[tokio::test]
   #[serial]
-  async fn test_default_post_language() -> Result<(), Error> {
+  async fn test_validate_post_language() -> LemmyResult<()> {
     let pool = &build_db_pool_for_tests();
     let pool = &mut pool.into();
     let (site, instance) = create_test_site(pool).await?;
@@ -613,8 +622,11 @@ mod tests {
     LocalUserLanguage::update(pool, test_langs2, local_user.id).await?;
 
     // no overlap in user/community languages, so defaults to undetermined
-    let def1 = default_post_language(pool, community.id, local_user.id).await?;
-    assert_eq!(UNDETERMINED_ID, def1);
+    let def1 = validate_post_language(pool, None, community.id, local_user.id).await;
+    assert_eq!(
+      Some(LemmyErrorType::LanguageNotAllowed),
+      def1.err().map(|e| e.error_type)
+    );
 
     let ru = Language::read_id_from_code(pool, "ru").await?;
     let test_langs3 = vec![
@@ -626,7 +638,7 @@ mod tests {
     LocalUserLanguage::update(pool, test_langs3, local_user.id).await?;
 
     // this time, both have ru as common lang
-    let def2 = default_post_language(pool, community.id, local_user.id).await?;
+    let def2 = validate_post_language(pool, None, community.id, local_user.id).await?;
     assert_eq!(ru, def2);
 
     Person::delete(pool, person.id).await?;