gerard.vermeulen@posteo.net writes:

>> I suspect that you may have some misunderstanding about how
>> `org-babel-detangle' works. Its docstring says:
>> 
>>    Propagate changes in source file back original to Org file.
>> 
>> So, it is expected to run from the tangled file; not from the Org file.
>
> Yes, I misunderstood this and I see that my patch breaks this.
>
> I think there is a typo in the docstring: "original to" must become "to 
> original"
> so that it ends with "back to original Org file".

How about the attached patch?