Prevent ALTER TABLE from being used to add a column with a REFERENCES clause and a non-NULL default value while foreign key support is enabled.

FossilOrigin-Name: 353b1b18253ab71ba38a887e555994f5469b87bd

test/fkey2.test

@@ -58,6 +58,8 @@ ifcapable {!foreignkey||!trigger} {
 # fkey2-13.*: Test that FK processing is performed when a row is REPLACED by
 #             an UPDATE or INSERT statement.
 #
+# fkey2-14.*: Test the ALTER TABLE and DROP TABLE commands.
+#
 # fkey2-genfkey.*: Tests that were used with the shell tool .genfkey
 #            command. Recycled to test the built-in implementation.
 #
@@ -737,6 +739,44 @@ do_test fkey2-13.1.4 {
   }
 } {2 2 2 3 2 3 1}
 
+#-------------------------------------------------------------------------
+# The following tests, fkey2-14.*, test that the "DROP TABLE" and "ALTER
+# TABLE" commands work as expected wrt foreign key constraints.
+#
+# fkey2-14.1*: ALTER TABLE ADD COLUMN
+# fkey2-14.2*: ALTER TABLE RENAME TABLE
+# fkey2-14.3*: DROP TABLE
+#
+drop_all_tables
+do_test fkey2-14.1 {
+  # Adding a column with a REFERENCES clause is not supported.
+  execsql { 
+    CREATE TABLE t1(a PRIMARY KEY);
+    CREATE TABLE t2(a, b);
+  }
+  catchsql { ALTER TABLE t2 ADD COLUMN c REFERENCES t1 }
+} {0 {}}
+do_test fkey2-14.2 {
+  catchsql { ALTER TABLE t2 ADD COLUMN d DEFAULT NULL REFERENCES t1 }
+} {0 {}}
+do_test fkey2-14.3 {
+  catchsql { ALTER TABLE t2 ADD COLUMN e REFERENCES t1 DEFAULT NULL}
+} {0 {}}
+do_test fkey2-14.4 {
+  catchsql { ALTER TABLE t2 ADD COLUMN f REFERENCES t1 DEFAULT 'text'}
+} {1 {Cannot add a REFERENCES column with non-NULL default value}}
+do_test fkey2-14.5 {
+  catchsql { ALTER TABLE t2 ADD COLUMN g DEFAULT CURRENT_TIME REFERENCES t1 }
+} {1 {Cannot add a REFERENCES column with non-NULL default value}}
+do_test fkey2-14.5 {
+  execsql { 
+    PRAGMA foreign_keys = off;
+    ALTER TABLE t2 ADD COLUMN h DEFAULT 'text' REFERENCES t1;
+    PRAGMA foreign_keys = on;
+    SELECT sql FROM sqlite_master WHERE name='t2';
+  }
+} {{CREATE TABLE t2(a, b, c REFERENCES t1, d DEFAULT NULL REFERENCES t1, e REFERENCES t1 DEFAULT NULL, h DEFAULT 'text' REFERENCES t1)}}
+
 #-------------------------------------------------------------------------
 # The following block of tests, those prefixed with "fkey2-genfkey.", are 
 # the same tests that were used to test the ".genfkey" command provided