sqldropindexes yields wrong indexes names when using postgresql_psycopg2

[anonymous]

If you are using a postgres database (with postgresql_psycopg2), and run:

./manage.py sqldropindexes example_app

The DROP INDEX commands printed have the index names wrong, with random strings at the end of them.

Example:

With these simple models:

class City(models.Model):
    name = models.CharField(max_length=50)

class Human(models.Model):
    name = models.CharField(max_length=50)
    city = models.ForeignKey(City)

If you run the sqlindexes command (which works ok), it outputs this:

./manage.py sqlindexes example_app
BEGIN;
CREATE INDEX "app_human_city_id" ON "app_human" ("city_id");

COMMIT;

But if you run the sqldropindexes command, it outputs this, which has the indexes names broken:

/manage.py sqldropindexes example_app
BEGIN;
DROP INDEX "app_human_b376980e" ;

COMMIT;

[anonymous]

I have tried in django 1.6, and the bug is present too.

[Tim Graham]

If confirmed, it's a candidate for backporting to 1.6 as it'd be a bug in a new feature, see d7429defe6f8d1dce49976cf49827d18ff6be025. However, the command is likely to be dropped in Django 2.0 along with apps without migrations as noted in this comment so if the fix is difficult, it may not be worth it.

[Aymeric Augustin]

The bug may be in sqlindexes, in which case the fix would not need to be backported.

[fisadev]

I was the reporter, forgot to log in. Just in case anybody needs extra info on how to reproduce it.

[Claude Paroz]

Duplicate of #22611