fix(blocklist): keep the cached name when a blocked user's profile fetch fails

apps/flipcash/shared/persistence/db/src/main/kotlin/com/flipcash/app/persistence/dao/UserProfileDao.kt

@@ -27,8 +27,10 @@ interface UserProfileDao {
      * Uses `INSERT OR REPLACE` with correlated sub-selects (rather than `ON CONFLICT DO
      * UPDATE`) so it works on the minSdk-29 SQLite build, which predates UPSERT. The
      * sub-selects read the current row before the replace, preserving every column the
-     * blocklist doesn't know about; the avatar keeps its existing value when [profilePicture]
-     * is null via COALESCE.
+     * blocklist doesn't know about. The name and avatar keep their existing values when
+     * [displayName] or [profilePicture] is null, via COALESCE: null means the caller has no
+     * profile to write (a failed fetch), whereas an empty name is one the user really has. A
+     * null name with nothing cached stores an empty one, since the column is NOT NULL.
      */
     @Query(
         """
@@ -38,7 +40,7 @@ interface UserProfileDao {
             profile_picture_json, username, pending_migration_json
         ) VALUES (
             :userIdHex,
-            :displayName,
+            COALESCE(:displayName, (SELECT display_name FROM user_profiles WHERE user_id_hex = :userIdHex), ''),
             (SELECT phone_value FROM user_profiles WHERE user_id_hex = :userIdHex),
             (SELECT phone_verified FROM user_profiles WHERE user_id_hex = :userIdHex),
             (SELECT email_value FROM user_profiles WHERE user_id_hex = :userIdHex),
@@ -50,7 +52,7 @@ interface UserProfileDao {
         )
         """
     )
-    suspend fun upsertNameAndAvatar(userIdHex: String, displayName: String, profilePicture: MediaItem?)
+    suspend fun upsertNameAndAvatar(userIdHex: String, displayName: String?, profilePicture: MediaItem?)
 
     /** The cached profile for [userIdHex], or null if none is cached. */
     @Query("SELECT * FROM user_profiles WHERE user_id_hex = :userIdHex LIMIT 1")

apps/flipcash/shared/persistence/db/src/test/kotlin/com/flipcash/app/persistence/UserProfileMigrationTest.kt

@@ -200,6 +200,37 @@ class UserProfileDaoTest {
         assertEquals("alice", dao.getByUserId("u1")?.username)
     }
 
+    @Test
+    fun `partial write with no name keeps the cached name`() = runBlocking {
+        val dao = db.userProfileDao()
+        dao.upsertFull(listOf(fullProfile("u1")))
+
+        // The blocklist writes no name when the profile fetch failed; that is not a rename.
+        dao.upsertNameAndAvatar(userIdHex = "u1", displayName = null, profilePicture = null)
+
+        assertEquals("Alice", dao.getByUserId("u1")?.displayName)
+    }
+
+    @Test
+    fun `partial write with no name and nothing cached stores an empty name`() = runBlocking {
+        val dao = db.userProfileDao()
+
+        dao.upsertNameAndAvatar(userIdHex = "u1", displayName = null, profilePicture = null)
+
+        assertEquals("", dao.getByUserId("u1")?.displayName)
+    }
+
+    @Test
+    fun `partial write with an empty name replaces the cached name`() = runBlocking {
+        val dao = db.userProfileDao()
+        dao.upsertFull(listOf(fullProfile("u1")))
+
+        // A fetched profile with no name is the user's own choice, not a failed lookup.
+        dao.upsertNameAndAvatar(userIdHex = "u1", displayName = "", profilePicture = null)
+
+        assertEquals("", dao.getByUserId("u1")?.displayName)
+    }
+
     @Test
     fun `chat member relation joins the shared normalized profile`() = runBlocking {
         db.userProfileDao().upsertFull(listOf(fullProfile("u1")))

apps/flipcash/shared/persistence/sources/src/main/kotlin/com/flipcash/app/persistence/sources/BlockedUserDataSource.kt

@@ -62,12 +62,13 @@ class BlockedUserDataSource @Inject constructor(
     /**
      * Writes the blocked user's name + avatar into the shared `user_profiles` table without
      * disturbing any richer profile already cached from a chat (the blocklist only resolves
-     * those two fields). See [com.flipcash.app.persistence.dao.UserProfileDao.upsertNameAndAvatar].
+     * those two fields). A null profile means the fetch failed, so the cached name stays rather
+     * than being blanked. See [com.flipcash.app.persistence.dao.UserProfileDao.upsertNameAndAvatar].
      */
     private suspend fun FlipcashDatabase.writeProfile(resolved: ResolvedBlockedUser) {
         userProfileDao().upsertNameAndAvatar(
             userIdHex = resolved.blocked.userId.hexEncodedString(),
-            displayName = resolved.profile?.displayName.orEmpty(),
+            displayName = resolved.profile?.displayName,
             profilePicture = resolved.profile?.profilePicture,
         )
     }