Don't register tables in metadata if autoloading fails

[Roman Podoliaka]

When autoloading of a table fails, it nevertheless gets added to the metadata registry. This behaviour seems to be accidentally introduced in f6198d9abf453182f4b111e0579a7a4ef1614e79.

Snippet to reproduce is attached. Fix is coming soon.

[Mike Bayer]

weird, that would be a regression. funny there's no test for that, need to put a test in test/engine/test_reflection. the code tries pretty hard to make sure this doesn't happen.

(looks)

oh geez I just commented out the line....need a test!

[Roman Podoliaka]

Sent a pull request via github, and the latter seems to be down now :)

[Roman Podoliaka]

Updated the pull request on github (https://github.com/zzzeek/sqlalchemy/pull/78). Let me know, if you think that the test is not sufficient.

[Mike Bayer]

Remove tables from metadata when autoload fails

If autoloading of a table fails, don't register it in a metadata instance. It seems that the original behaviour was accidentally changed in f6198d9abf453182f4b111e0579a7a4ef1614e79, restore it.

Closes issue #2988

→ <<cset 0bb00db55812>>

[Mike Bayer]

changelog to fix #2988

→ <<cset c464960fddf0>>