Use feature timeout when starting second engine for analysis

When the second engine gets ivolved in the analysis, but has not been
used before, so that its features are unknown, we now wait for these
features (or time out in case of v1 engines) before initializing the
engine. Without this 'edit' could be used on engines that need 'setboard',
or false 'unsupported variant' errors could arise.

diff --git a/backend.c b/backend.c
index 29b473b..4f1aad8 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -14784,18 +14784,25 @@ EditTagsEvent ()
 }
 
 void
-ToggleSecond ()
+StartSecond ()
 {
-  if(second.analyzing) {
-    SendToProgram("exit\n", &second);
-    second.analyzing = FALSE;
-  } else {
-    if (second.pr == NoProc) StartChessProgram(&second);
+    if(WaitForEngine(&second, StartSecond)) return;
     InitChessProgram(&second, FALSE);
     FeedMovesToProgram(&second, currentMove);
 
     SendToProgram("analyze\n", &second);
     second.analyzing = TRUE;
+    ThawUI();
+}
+
+void
+ToggleSecond ()
+{
+  if(second.analyzing) {
+    SendToProgram("exit\n", &second);
+    second.analyzing = FALSE;
+  } else {
+    StartSecond();
   }
 }
 
@@ -17398,7 +17405,7 @@ FeatureDone (ChessProgramState *cps, int val)
   DelayedEventCallback cb = GetDelayedEvent();
   if ((cb == InitBackEnd3 && cps == &first) ||
       (cb == SettingsMenuIfReady && cps == &second) ||
-      (cb == LoadEngine) ||
+      (cb == LoadEngine) || (cb == StartSecond) ||
       (cb == TwoMachinesEventIfReady)) {
     CancelDelayedEvent();
     ScheduleDelayedEvent(cb, val ? 1 : 3600000);