If we meet when I come to Paris next year, you can show me your city.

For example, I'm going to Paris next year. In Paris lives my acquaintance Helene. I say to her on the phone:

If we meet when I come to Paris next year, you can show me your city.

I know, on the basis of Google's search results, that "If we meet when I come to Paris" is wrong. Surely, I could say: I'm going to Paris next year. So if we meet, you can show me your city. But what should I say if I want to underline the "when I come to Paris next year" idea and at the same time cram all that into one sentence? That is, it comes out that one subordinate clause (If we meet) must have another one (when I come to Paris next year).
However, mostly, I'm interested in how a native English speaker would say all that idea.

Why or how is "If we meet when I come to Paris, ..." wrong as a clause?

As a clause, it looks fine to me.

For me, a subjunctive would seem natural as the completion. Such as "If we meet when I come to Paris, perhaps you could show me your city."

There are lots of ways to frame this.

If we should meet when I'm in Paris next year, you could show me your favourite places.

Or as a question "If we should meet when I'm in Paris next year, would you show me your favourite places?" or 'some of the sights' etc.

If we should meet -- suggests only a very slight possibility that we will meet.

there is nothing wrong with
If we meet when I come to Paris next year, you can show me your city.

That's exactly how I'd say it.

Thanks a lot!

I simply looked at the search results and decided there was some mistake there.

Then I'll ask you one more thing at the same time. When I say If we meet when I come to Paris next year, does it mean that 1) I sort of arrive to the airport and she is there waiting for me or 2) I go to Paris, have been living for a while there and then we meet? Simply, It now confuses me that "come" is used in Present Simple instead of Present Perfect Simple as the second option I have meant in my first post.

This is more like future conditional: (copied from another site)

"Future Conditionals
Future Real Conditional
FORM

[If / When ... Simple Present ..., ... Simple Future ...]

[... Simple Future ... if / when ... Simple Present ...]

Notice that there is no future in the if- or when-clause.
USE

The Future Real Conditional describes what you think you will do in a specific situation in the future. It is different from other Real Conditional forms because, unlike the present or the past, you do not know what will happen in the future. Although this form is called "real", you are usually imagining or guessing about the future. It is called "real" because it is still possible that the action might occur in the future."

"If we meet when I come to Paris next year" is not defined well enough to say much about the conditions of meeting. It would seem for that, more explanation or more details, or other requests or suggestions would help.

That is, it would be better to actually ask to meet at the airport, or ask about some other kind of provisional plan.

Sorry! I've written Past Simple instead Present Simple there. I meant "...that "come" is used in Present Simple instead of Present Perfect Simple... " That is, I think that when I say

If we meet when I come to Paris next year,

it means that I sort of arrive to the airport and she is there waiting for me (i.e. we meet in that way).

but when I say

If we meet when I have come to Paris next year

it signifies that I go to Paris, have been living for a while there and then we meet.

Or am I wrong and If we meet when I come to Paris next year mean that I go to Paris, have been living for a while there and then we meet?

Well, Oldboy, it seems that there is a little problem with the verb 'to come'. In English, it is somewhat indeterminant. A little like the Russian indeterminant verbs. For the meanings you are interested in, a more determinant verb might be useful, to clarify things a little. Maybe the verb 'to arrive' would be better. Or the deverbal 'arrival'.

'If we meet when I have arrived in Paris next year' or 'If we meet on my arrival in Paris next year' These woud have much more of the sense you are looking for when you say this "it means that I sort of arrive to the airport and she is there waiting for me (i.e. we meet in that way)."

For this one: "mean that I go to Paris, have been living for a while there and then we meet?" a verb like 'to settle' or 'find lodgings' might work:

If we meet when I have settled in Paris next year -or- If we meet after I have settled in Paris next year

If we meet after I have found lodgings in Paris next year

Are these the kinds of different shades of meaning you're looking for?

'To come' is simply too indeterminant to pin down precisely to the kinds of meanings you have asked about.

It will might be more understandable in that way. When I say "If we meet when I come in Paris next year" does it mean:

1) that I will arrive to the airport and she will have been waiting for me there (and it's at the airport that we will meet)

or

2) that I will go to Paris, have been living there for a while and then we will meet

or something else?