Within the EU, it is important to note that the grounds for preventing an EU citizen from entering another EU country - or for expelling them from another EU country - are extremely limited. A conviction, even for a serious crime, is not enough - the other country has to prove you pose a concrete threat.
So Germany, France, Portugal or any other country cannot deny you entry based on having a conviction. They would need evidence that you pose a present risk to public security in that country.
You can find more information on this in EU documentation for things like the Schengen Borders Code, Schengen Information System, and the EU's website on citizens' rights, which features sections on when an EU citizen can be denied entry to an EU country that they are not a citizen of.
One thing I found (from http://ec.europa.eu/citizensrights/front_end/docs/faq.pdf
Quote: As an EU citizen, you are free to enter and reside, subject to some conditions, in the other EU countries. This fundamental right of free movement can be restricted on grounds of public security, public health and public order. However, this restriction must be interpreted strictly
, and it is only on grounds of present and serious threat to public security
that you can be forbidden to enter another EU country. The mere existence of past convictions is not sufficient.
As an example, see this case involving an Italian citizen convicted of murder in the UK, whom the UK wanted to deport at the end of his sentence in UK prison. He challenged the deportation under EU freedom of movement rules, and won. The UK could not deport him as the murder he committed took place many years prior and he had not proven to be a present and serious