Stamp should ignore bad branch or revision

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create a migration who's version number we'll refer to as 'ver' and upgrade 
to it.
2. Switch source control branch (like git) to a version without the previous 
migration.
3. Run alembic current, see error.  Try to alembic stamp the correct version to 
fix it, see the same error.

What is the expected output? What do you see instead?
I should be able to stamp to fix the issue.  But it fails because I can't 
stamp.  I get an error in the format "FAILED: No such revision or branch 
'ver'".  It can only be fixed by directly altering the current version data.

What version of the product are you using? On what operating system?
Alembic, Ubuntu 14

Original issue reported on code.google.com by ThinkGa...@gmail.com on 16 Jul 2015 at 5:08

[GoogleCodeExporter]

Wrong Alembic project.

Original comment by miller.lucas on 16 Jul 2015 at 5:17

• Changed state: Invalid