id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30039	Inconsistency error after unapplying squash migration.	Shehzad-Ahmed	nobody	"Just for reminder: Migrations contain parent migrations called dependencies. So when an parent migration is rolled back all of its  successors are also rolled back. For the consistency django make record of all applied and rolled back(unapplied) migrations. Now before any new migration is applied consistency is checked.

Just for reminder: In Case when a squash migration is created, a list inside it is maintained which tracks all migrations it replaced called replaces.

Problem: when a squash migration is rolled back all its replaces(which can be dependencies or depended on other migrations) are marked UN-applied but squash migration migration it-self does not record UN-applied. Since the operation of rolling back squash migration becomes completed. But Then when new migrate operation is performed, it causes inconsistency error e.g below:

""django.db.migrations.exceptions.InconsistentMigrationHistory: Migration compliance.0007_auto_20180329_1238_squashed_0026_auto_20180815_0741 is applied before its dependency survey.0092_prospectfarmerviewlinkcompliancelink on database 'default' ."""	Bug	closed	Migrations	2.1	Normal	worksforme	Squash migration, replaces, rolled back(UN-applied)		Unreviewed	1	0	1	0	0	0