Math postdoc at home university I am a math postdoc in Europe, and have been a postdoc for the last 6 years. Unfortunetly, I was still not able to obtain a tenure track position 
(I was very close to get one, but because of bad luck will have to try again next year). 

My current postdoc position ends in a few months. Because I thought that I will get a tenure-track position this year, I did not bother to search for a new post doc position until very late in the year. As a result, in a few months I will not have a postdoc position.

My Phd advisor came to the rescue - He can fund me as a postdoc at the University I did my phd in.

I would like to ask if people will look bad on someone that goes do a postdoc with his advisor in future job searches?

I should mention that I did not work with my advisor at all after my Phd, and am very independent in my research. Still, I am worried about this, and wonder what people think about such a situation.

Thank you
I wouldn't turn down the position with your advisor out of concern for how it will look at your CV.  It's hard to know for sure what will trigger a negative reaction in any one specific person; there are a lot of different people on hiring committees so it's very hard to absolutely rule out the possibility.  But precisely because of that, you can't let the possibility of something looking bad paralyze you, since almost anything could.  Someone once pointed out to me that there are certain things on one's CV that "look bad" but only really to people who are looking for some excuse to knock you down; if you don't give them that thing to take a hold of, they will surely just find something else.  

Furthermore, I think the possibility of having a CV that suggests a charmed path of continuous success is a horse which has already left the barn.  If someone is going to hold a postdoc with your advisor against you, they could also certainly hold being on your 7th year of postdoc, or whatever number you had done; certainly if there's a gap between the end of your current job and the next one, they can hold that against you.  I would take whatever path is going to give you the best short term chance to do good research; that's what your job search next year will be based on, not exactly what path you took while doing it.