I'll tell you. Whilst living near the City of Mulhouse in Alsace, I saw how French people treated Algerian youths, especially the CRS. See for yourself then comment!. You think the Met Police had problems with institutional racism!!!
I've not lived in France but I have been interested in their politics and the reaction and subsequent bombing of the French mainland by Algerian groups who believed France were supporting the Algerian government repressing them has swung french opinion. In my opinion every country has it's problems (germany mainly turks, spannish mainly Morrocans, etc) but the French reaction which can be firm at times and pure racist at it's worst has exacerbated the problem. The race riots in France a few months ago highlighted this, hundreds of cars burning a night. This is because, believe or not, they're not given the same support as a "french person". People may disagree but in my opinion legal immigration into this country should not be discouraged, they give something to us and we give the same back. It's stereotyping but I'd rather let someone in to drive a minicab at 3am in the morning than have a pure white brit sat around on the dole and not prepared to work for a living... That is stereotyping in the extreme and should not be taken too literally.
Anyway, basically the French have ignored the problems far too long and it's coming back up to bite them on the backside
It is rather more complex than you seem to wish to care to admit.
Immigrants of Algerian origin are often treated very badly, marginalising and brutalising them; many immigrants of Algerian origin behave appallingly, reinforcing the prejudices of the white majority. Something of a chicken and egg situation.
I was a little surprised when you thought that this was the sort of thing that might happen to Algerians when this is set against the record of anti-semitic violence by elements of this group. You may recall the bombings of the Paris metro; I recall in particular the attempted GIA bombing of a Jewish primary school in Lyon. To these incidents should be added the routine desecration of cemeteries.
I lived in the first arrondisement of Lyon for some time, arriving with a fairly open mind, tending to the view that the French were appallingly racist. My sympathy towards Arab youths was to be sorely tested. I returned to England extremely thankful that we did not have problems on anything like the same scale.