Report a distinct error code for sync connection timeouts (#6932)

The same error code was used for both timeouts and other connection failures,
and the error reported always had an empty message.

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ### Enhancements
 * <New feature description> (PR [#????](https://github.com/realm/realm-core/pull/????))
-* None.
+* Add a distinct error code for timeouts (SyncConnectTimeout) rather than using the same one as for less transient failures ([PR #6932](https://github.com/realm/realm-core/pull/6932)).
 
 ### Fixed
 * <How do the end-user experience this issue? what was the impact?> ([#????](https://github.com/realm/realm-core/issues/????), since v?.?.?)

src/realm/error_codes.cpp

@@ -64,6 +64,7 @@ ErrorCategory ErrorCodes::error_categories(Error code)
             return ErrorCategory().set(ErrorCategory::runtime_error).set(ErrorCategory::sync_error);
 
         case SyncConnectFailed:
+        case SyncConnectTimeout:
         case SyncProtocolNegotiationFailed:
         case TlsHandshakeFailed:
             return ErrorCategory()
@@ -383,6 +384,7 @@ static const MapElem string_to_error_code[] = {
     {"SyncClientResetRequired", ErrorCodes::SyncClientResetRequired},
     {"SyncCompensatingWrite", ErrorCodes::SyncCompensatingWrite},
     {"SyncConnectFailed", ErrorCodes::SyncConnectFailed},
+    {"SyncConnectTimeout", ErrorCodes::SyncConnectTimeout},
     {"SyncInvalidSchemaChange", ErrorCodes::SyncInvalidSchemaChange},
     {"SyncPermissionDenied", ErrorCodes::SyncPermissionDenied},
     {"SyncProtocolInvariantFailed", ErrorCodes::SyncProtocolInvariantFailed},

src/realm/error_codes.h

@@ -73,15 +73,16 @@ typedef enum realm_errno {
     RLM_ERR_SYNC_CLIENT_RESET_REQUIRED = 1032,
     RLM_ERR_SYNC_COMPENSATING_WRITE = 1033,
     RLM_ERR_SYNC_CONNECT_FAILED = 1034,
-    RLM_ERR_SYNC_INVALID_SCHEMA_CHANGE = 1035,
-    RLM_ERR_SYNC_PERMISSION_DENIED = 1036,
-    RLM_ERR_SYNC_PROTOCOL_INVARIANT_FAILED = 1037,
-    RLM_ERR_SYNC_PROTOCOL_NEGOTIATION_FAILED = 1038,
-    RLM_ERR_SYNC_SERVER_PERMISSIONS_CHANGED = 1039,
-    RLM_ERR_SYNC_USER_MISMATCH = 1040,
-    RLM_ERR_TLS_HANDSHAKE_FAILED = 1041,
-    RLM_ERR_WRONG_SYNC_TYPE = 1042,
-    RLM_ERR_SYNC_WRITE_NOT_ALLOWED = 1043,
+    RLM_ERR_SYNC_CONNECT_TIMEOUT = 1035,
+    RLM_ERR_SYNC_INVALID_SCHEMA_CHANGE = 1036,
+    RLM_ERR_SYNC_PERMISSION_DENIED = 1037,
+    RLM_ERR_SYNC_PROTOCOL_INVARIANT_FAILED = 1038,
+    RLM_ERR_SYNC_PROTOCOL_NEGOTIATION_FAILED = 1039,
+    RLM_ERR_SYNC_SERVER_PERMISSIONS_CHANGED = 1040,
+    RLM_ERR_SYNC_USER_MISMATCH = 1041,
+    RLM_ERR_TLS_HANDSHAKE_FAILED = 1042,
+    RLM_ERR_WRONG_SYNC_TYPE = 1043,
+    RLM_ERR_SYNC_WRITE_NOT_ALLOWED = 1044,
 
     RLM_ERR_SYSTEM_ERROR = 1999,
 

src/realm/error_codes.hpp

@@ -116,6 +116,7 @@ class ErrorCodes {
         SyncClientResetRequired = RLM_ERR_SYNC_CLIENT_RESET_REQUIRED,
         SyncCompensatingWrite = RLM_ERR_SYNC_COMPENSATING_WRITE,
         SyncConnectFailed = RLM_ERR_SYNC_CONNECT_FAILED,
+        SyncConnectTimeout = RLM_ERR_SYNC_CONNECT_TIMEOUT,
         SyncInvalidSchemaChange = RLM_ERR_SYNC_INVALID_SCHEMA_CHANGE,
         SyncPermissionDenied = RLM_ERR_SYNC_PERMISSION_DENIED,
         SyncProtocolInvariantFailed = RLM_ERR_SYNC_PROTOCOL_INVARIANT_FAILED,

src/realm/sync/noinst/client_impl_base.cpp

@@ -804,8 +804,10 @@ void Connection::handle_connect_wait(Status status)
 
     REALM_ASSERT_EX(m_state == ConnectionState::connecting, m_state);
     logger.info("Connect timeout"); // Throws
-    involuntary_disconnect(SessionErrorInfo{Status{ErrorCodes::SyncConnectFailed, status.reason()}, IsFatal{false}},
-                           ConnectionTerminationReason::sync_connect_timeout); // Throws
+    involuntary_disconnect(
+        SessionErrorInfo{Status{ErrorCodes::SyncConnectTimeout, "Sync connection was not fully established in time"},
+                         IsFatal{false}},
+        ConnectionTerminationReason::sync_connect_timeout); // Throws
 }