constraint equal reverted

go/libraries/doltcore/schema/alterschema/droppk.go

@@ -40,9 +40,9 @@ func DropPrimaryKeyFromTable(ctx context.Context, table *doltdb.Table, nbf *type
 	newCollection := schema.MapColCollection(sch.GetAllCols(), func(col schema.Column) schema.Column {
 		col.IsPartOfPK = false
 		// Removing PK does not remove NOT NULL constraint, so add it back if it's somehow gone
-		if col.IsNullable() {
-			col.Constraints = append(col.Constraints, schema.NotNullConstraint{})
-		}
+		//if col.IsNullable() {
+		//	col.Constraints = append(col.Constraints, schema.NotNullConstraint{})
+		//}
 		return col
 	})
 

go/libraries/doltcore/schema/constraint.go

@@ -93,6 +93,12 @@ func IndexOfConstraint(constraints []ColConstraint, constraintType string) int {
 // ColConstraintsAreEqual validates two ColConstraint slices are identical.
 func ColConstraintsAreEqual(a, b []ColConstraint) bool {
 	// kinda shitty.  Probably shouldn't require order to be identical
+	if len(a) != len(b) {
+		return false
+	} else if len(a) == 0 {
+		return true
+	}
+
 	for i := 0; i < len(a); i++ {
 		ca, cb := a[i], b[i]
 

go/libraries/doltcore/schema/encoding/schema_marshaling.go

@@ -63,7 +63,7 @@ func encodeAllColConstraints(constraints []schema.ColConstraint) []encodedConstr
 	for _, c := range constraints {
 		if c.GetConstraintType() == schema.NotNullConstraintType {
 			if seenNotNull {
-				continue
+				//continue
 			}
 			seenNotNull = true
 		}