Strengthen check for invalid columns.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>

lib/newfol/database.py

@@ -371,8 +371,10 @@ class Schema:
             elif rectype in ['col', 'column']:
                 try:
                     self._columns = int(i.fields[1])
+                    if self._columns <= 0:
+                        raise ValueError
                 except ValueError:
-                    raise newfol.exception.SchemaError("has non-integral " +
+                    raise newfol.exception.SchemaError("has invalid " +
                                                        "number of columns")
             elif rectype in ['txn', 'transaction']:
                 self._txntype = i.fields[1:]

test/testdatabase.py

@@ -1,5 +1,6 @@
 #!/usr/bin/python3
 
+from newfol.exception import SchemaError
 from newfol.database import DatabaseVersion, Database, Schema, Singleton
 from newfol.filemanip import Record
 import tempfile
@@ -169,6 +170,22 @@ class TestExtraSchemaConfig(unittest.TestCase):
         # Ensure no exception is raised.
 
 
+class TestSchemaColumns(unittest.TestCase):
+    def check_invalid(self, value):
+        with self.assertRaises(SchemaError):
+            tdb = TemporaryDatabase("col:%s\n" % value)
+            tdb.db
+
+    def test_non_integral(self):
+        self.check_invalid(3.5)
+
+    def test_negative(self):
+        self.check_invalid(-1)
+
+    def test_zero(self):
+        self.check_invalid(0)
+
+
 class TestExecutionAllowed(unittest.TestCase):
     def do_test(self, expected, schema, configv):
         tdb = TemporaryDatabase(schema)