Merge data node getting triggered even without data input from both source

I have a merge node in my work flow and it is coupled with a if-else node. What i want is sub-flow ivloving merge data node should only be executed at certain case.But merge node is getting triggered even if there is no data output from the previous if-else not to the sub-flow. Is is desirable or a bug ?

Yes, that is sadly a known issue. It had to behave that way because else it blocked the execution in some other cases.

There is already a fix for that, sadly it is also half a breaking change, as it totally changes how n8n workflows execute. So will be released with n8n version 1.0.

Here the PR for reference.

You could try to add a NoOp node between the nodes IF and `True case. This could maybe help to get the desired effect

thank you, i have found an alternate way to achieve the same objective without using the merge node.