Fix bug with repeated log event subscription (#439)

rowan-walsh · web-flow · commit 1db8318debdd · 2025-02-01T16:39:59.000+11:00
The bug was caused by the alreadySubscribedToEvents flag not being set
after a successful log event subscription. This meant that
plc_tag_register_logger() could be called multiple times, causing an
error.
diff --git a/src/libplctag/LibPlcTag.cs b/src/libplctag/LibPlcTag.cs
@@ -66,6 +66,8 @@ static private void ensureSubscribeToEvents()
             var statusAfterRegistration = (Status)_native.plc_tag_register_logger(loggerDelegate);
             if (statusAfterRegistration != Status.Ok)
                 throw new LibPlcTagException(statusAfterRegistration);
+
+            alreadySubscribedToEvents = true;
         }
 
         static void invokeLogEvent(int tag_id, int debug_level, string message)

Original file line number	Diff line number	Diff line change
`@@ -66,6 +66,8 @@ static private void ensureSubscribeToEvents()`
`66`	`66`	`var statusAfterRegistration = (Status)_native.plc_tag_register_logger(loggerDelegate);`
`67`	`67`	`if (statusAfterRegistration != Status.Ok)`
`68`	`68`	`throw new LibPlcTagException(statusAfterRegistration);`
	`69`	`+`
	`70`	`+ alreadySubscribedToEvents = true;`
`69`	`71`	`}`
`70`	`72`
`71`	`73`	`static void invokeLogEvent(int tag_id, int debug_level, string message)`