Fixed #19341 -- Detected NullBooleanField when introspecting models

Thanks Tim Bowden for the report.

django/core/management/commands/inspectdb.py

@@ -108,6 +108,9 @@ class Command(NoArgsCommand):
                 # Add 'null' and 'blank', if the 'null_ok' flag was present in the
                 # table description.
                 if row[6]: # If it's NULL...
+                    if field_type == 'BooleanField(':
+                        field_type = 'NullBooleanField('
+                    else:
                         extra_params['blank'] = True
                         if not field_type in ('TextField(', 'CharField('):
                             extra_params['null'] = True

tests/regressiontests/inspectdb/models.py

@@ -34,6 +34,7 @@ class ColumnTypes(models.Model):
     id = models.AutoField(primary_key=True)
     field1 = models.BigIntegerField()
     field2 = models.BooleanField()
+    field2b = models.NullBooleanField()
     field3 = models.CharField(max_length=10)
     field4 = models.CommaSeparatedIntegerField(max_length=99)
     field5 = models.DateField()
@@ -46,7 +47,6 @@ class ColumnTypes(models.Model):
     field12 = models.IntegerField()
     field13 = models.IPAddressField()
     field14 = models.GenericIPAddressField(protocol="ipv4")
-    field15 = models.NullBooleanField()
     field16 = models.PositiveIntegerField()
     field17 = models.PositiveSmallIntegerField()
     field18 = models.SlugField()

tests/regressiontests/inspectdb/tests.py

@@ -39,8 +39,10 @@ class InspectDBTestCase(TestCase):
         if connection.vendor == 'mysql':
             # No native boolean type on MySQL
             assertFieldType('field2', "models.IntegerField()")
+            assertFieldType('field2b', "models.IntegerField(null=True, blank=True)")
         else:
             assertFieldType('field2', "models.BooleanField()")
+            assertFieldType('field2b', "models.NullBooleanField()")
         assertFieldType('field3', "models.CharField(max_length=10)")
         # CommaSeparatedIntegerField
         assertFieldType('field4', "models.CharField(max_length=99)")
@@ -68,8 +70,6 @@ class InspectDBTestCase(TestCase):
         else:
             assertFieldType('field13', "models.CharField(max_length=15)")
             assertFieldType('field14', "models.CharField(max_length=39)")
-        # Ticket #19341
-        #assertFieldType('field15', "models.NullBooleanField()")
         if connection.vendor == 'sqlite':
             assertFieldType('field16', "models.PositiveIntegerField()")
             assertFieldType('field17', "models.PositiveSmallIntegerField()")