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
26819	"Using a ArrayField on Meta.unique_together throws ""unhashable type: 'list'"" on validate_unique method"	Gleber Diniz	Demur Nodia	"It happens on a second save (when there is already data to be validated)

On this line: ""if row_data in seen_data:"", because row_data contains a list and seen_data is a set (row_data: (1, [1, 1]) / seen_data: set())

Example to reproduce:

models:
{{{#!python
class Map(models.Model):
    name = models.CharField('name', max_length=128)


class MapSpot(models.Model):
    map = models.ForeignKey('body.Map', related_name='spots')
    position = ArrayField(models.IntegerField(), size=2)

    class Meta:
        unique_together = [('map', 'position')]
}}}

admin:
{{{#!python
class MapSpotInline(admin.TabularInline):
    model = MapSpot
    extra = 0


@admin.register(Map)
class MapAdmin(admin.ModelAdmin):
    inlines = [MapSpotInline]
}}}"	Bug	closed	Forms	dev	Normal	fixed			Accepted	1	0	0	0	0	0