Distinguish failed member-link snapshots from confirmed disconnection

tools/chatgui-android/app/src/main/java/com/utun/chat/data/ChatRepository.kt

@@ -474,9 +474,15 @@ class ChatRepository(private val reportFailure: (String) -> Unit = { LogManager.
 
     fun deleteChannel(channelId: String) = NativeLib.deleteChannel(channelId)
 
-    fun getMemberLinks(nodeId: Long): MemberLinks {
+    fun getMemberLinks(nodeId: Long): MemberLinks? {
+        return try { parseMemberLinks(NativeLib.getMemberLinks(nodeId)) }
+        catch (e: Exception) { reportFailure("Member links unavailable node=$nodeId: $e"); null }
+    }
+
+    /** null — ошибка снимка, {cn:false} либо {} — подтверждённое отсутствие соединения. */
+    internal fun parseMemberLinks(json: String): MemberLinks? {
         try {
-            val obj = JSONObject(NativeLib.getMemberLinks(nodeId))
+            val obj = JSONObject(json)
             if (!obj.optBoolean("cn", false)) return MemberLinks()
             val links = mutableListOf<LinkStatus>()
             val arr = obj.optJSONArray("lk")
@@ -505,8 +511,8 @@ class ChatRepository(private val reportFailure: (String) -> Unit = { LogManager.
                 linksUp = obj.optInt("lu", 0),
                 links = links
             )
-        } catch (e: Exception) { reportFailure("Member links failed node=$nodeId: $e") }
-        return MemberLinks()
+        } catch (e: Exception) { reportFailure("Member links snapshot failed: $e") }
+        return null
     }
 
     fun parseLocalSockets(json: String): List<LocalSocketState>? {

tools/chatgui-android/app/src/test/java/com/utun/chat/data/ChatRepositorySnapshotTest.kt

@@ -33,4 +33,16 @@ class ChatRepositorySnapshotTest {
         assertEquals(emptyList<LocalSocketState>(), repo.parseLocalSockets("[]"))
         assertEquals(before, repo.parseLocalSockets("[$row]"))
     }
+
+    @Test fun brokenLinkSnapshotDoesNotTurnAConnectedPeerIntoDisconnected() {
+        val row = """{"cn":true,"in":true,"lu":1,"lk":[{"id":9,"st":3,"sn":"Wi-Fi 😀"}]}"""
+        val connected = repo.parseMemberLinks(row)!!
+        assertTrue(connected.connected)
+        assertEquals("Wi-Fi 😀", connected.links.single().socketName)
+        assertNull(repo.parseMemberLinks("""{"cn":true,"lk":[{},null]}"""))
+        assertTrue(errors.single().contains("Member links snapshot failed"))
+        assertEquals(MemberLinks(), repo.parseMemberLinks("{}"))
+        assertEquals(MemberLinks(), repo.parseMemberLinks("""{"cn":false}"""))
+        assertEquals(connected, repo.parseMemberLinks(row))
+    }
 }