inspectdb to quote ForeignKey class names to avoid need to reorder classes/solve circular dependencies

[saschwarz]

The inspectdb management command supplies either "self" or the unquoted name of foreign key's class as the first argument to the ForeignKey constructor. This requires that classes be defined prior to their first use. If the class name were supplied as a quoted string the ordering of classes isn't required. That would also solve the case where circular dependencies keep classes from being defined in an appropriate order.

I've attached the trivial changes as a diff from trunk 15194.

[Ramiro Morales]

If I remember correctly, specifying the FK destination model name inside quotes doesn't work well when the model is already known, so a general solution like this (always using quoting) can result in faulty introspected models.py's.

[jeff@…]

Quote ForeignKey models only if the model has not appeared yet.

[jeff@…]

Please see attached patch; it only quotes model names if the model has not yet been written out. Is that an acceptable deal? It should prevent quoting known model names but still quote model names that have not been initialized yet.

[Aymeric Augustin]

#16476 was a duplicate. And yes, it sounds like a good idea.

[Ramiro Morales]

#9164 was a duplicate.

[Claude Paroz]

Identical patch + updated test

[Claude Paroz]

In [17942]:

Fixed #15076 -- Quoted ForeignKey target class names in inspectdb when class is defined below.

Thanks saschwarz for the report, jeff@… for the initial patch and Ramiro Morales for the review.