Summary

Fix evolution optimization issues when renaming models.

Review Request #8085 — Created March 30, 2016 and submitted April 1, 2016, 6:55 p.m.

Information

Owner

chipx86

Repository

Django Evolution

Branch

release-0.7.x

Bugs

Depends On

Commit

df2ba20...

Reviewers

Groups

django-evolution

People

Description

Django Evolution's evolution optimization code had issues when applying
a series of evolutions that add a ForeignKey field to a newly-introduced
model that is then renamed in the same batch. The resulting field would
still point to the original model, resulting in a KeyError.

This was partly caused by the optimization code not attempting to update
the related_model attribute of the new field when merging field
attributes, and partly due to the RenameModel mutation not being
available during the evolution process for a newly-introduced model (due
to it being filtered out earlier on).

This change fixes this by adding code for tracking model renames and
deletions, ensuring the RenameModel is always present in the
optimization steps, and making sure that related_model attribute is set
for newly-introduced fields when the specified model has been renamed.

Optimizations were also added to condense model renames, and to remove
any mutations that rename models that will later be deleted.

Testing Done

Unit tests pass for SQLite, MySQL, and PostgreSQL.

Tested against a database that hit this particular bug. I received a
KeyError before the fix, but after, I was able to successfully upgrade.

Issues

Description	From	Last Updated
list comprehension redefines 'model_name' from line 722	reviewbot	March 30, 2016, 4:15 p.m.
list comprehension redefines 'model_name' from line 638	reviewbot	March 30, 2016, 4:18 p.m.
This sentence isn't 100% grammar.	david	March 30, 2016, 5:37 p.m.

Tool: Pyflakes
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py



Tool: PEP8 Style Checker
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py

django_evolution/mutators.py (Diff revision 1)
The issue has been resolved. Show all issues
```
 list comprehension redefines 'model_name' from line 722
```

Change Summary:


Fixed a harmless reused variable warning by simplifying a small block of code.

Commit:

e9ff42650025df6a51d773849db753075c629a33

8bf09d090d0617471663d2adbc8a3c4430123baa

Diff:

Revision 2 (+451 -9)

Show changes

	django_evolution/evolve.py
	django_evolution/mutators.py
	django_evolution/tests/test_preprocessing.py
	django_evolution/tests/db/mysql.py
	django_evolution/tests/db/postgresql.py
	django_evolution/tests/db/sqlite3.py

Tool: Pyflakes
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py



Tool: PEP8 Style Checker
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py

django_evolution/mutators.py (Diff revision 2)
The issue has been resolved. Show all issues
```
 list comprehension redefines 'model_name' from line 638
```

Change Summary:

Fixed one more harmless warning about a reused variable name by renaming the variable.

Commit:

8bf09d090d0617471663d2adbc8a3c4430123baa

1f7432766b5f0eb5e7596896f705861e687b9261

Diff:

Revision 3 (+452 -9)

Show changes

	django_evolution/evolve.py
	django_evolution/mutators.py
	django_evolution/tests/test_preprocessing.py
	django_evolution/tests/db/mysql.py
	django_evolution/tests/db/postgresql.py
	django_evolution/tests/db/sqlite3.py

Tool: Pyflakes
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py



Tool: PEP8 Style Checker
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py

Ship it!

django_evolution/mutators.py (Diff revision 3)
The issue has been resolved. Show all issues
```
This sentence isn't 100% grammar.
```
1. chipx86 March 30, 2016, 5:36 p.m.
  It's 100% some kind of grammar!

Change Summary:

Grammars now super good.

Commit:

1f7432766b5f0eb5e7596896f705861e687b9261

df2ba2007ab0b267a826092f0dc4af1164e92006

Diff:

Revision 4 (+452 -9)

Show changes

	django_evolution/evolve.py
	django_evolution/mutators.py
	django_evolution/tests/test_preprocessing.py
	django_evolution/tests/db/mysql.py
	django_evolution/tests/db/postgresql.py
	django_evolution/tests/db/sqlite3.py

Tool: Pyflakes
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py



Tool: PEP8 Style Checker
Processed Files:
    django_evolution/tests/db/sqlite3.py
    django_evolution/tests/db/postgresql.py
    django_evolution/mutators.py
    django_evolution/tests/test_preprocessing.py
    django_evolution/evolve.py
    django_evolution/tests/db/mysql.py

Ship it!

```
Ship It!
```

Status:: Completed
Change Summary:: Pushed to release-0.7.x (5ce1c47)