pytest: fix the invoice typo migration if you ran and created both.

Signed-off-by: Rusty Russell <[email protected]>

tests/test_invoices.py

@@ -926,7 +926,6 @@ def test_invoices_wait_db_migration(node_factory, bitcoind):
     l2.rpc.invoice(1000, "test", "test")
 
 
-@pytest.mark.xfail(strict=True)
 def test_invoice_botched_migration(node_factory, chainparams):
     """Test for grubles' case, where they ran successfully with the wrong var: they have *both* last_invoice_created_index *and *last_invoices_created_index* (this can happen if invoice id 1 was deleted, so they didn't die on invoice creation):
     Error executing statement: wallet/db.c:1684: UPDATE vars SET name = 'last_invoices_created_index' WHERE name = 'last_invoice_created_index': UNIQUE constraint failed: vars.name

wallet/db.c

@@ -1679,10 +1679,35 @@ static void migrate_initialize_wait_indexes(struct lightningd *ld,
 static void migrate_invoice_created_index_var(struct lightningd *ld, struct db *db)
 {
 	struct db_stmt *stmt;
+	s64 badindex, realindex;
+
+	/* Prior migration had a typo!  But we might have run since
+	 * then and created an invoice, so we have to set the real one
+	 * to the max of the two... */
+	badindex = db_get_intvar(db, "last_invoice_created_index", -1);
+	realindex = db_get_intvar(db, "last_invoices_created_index", -1);
+
+	/* Bad index does not exist?  Fine */
+	if (badindex < 0)
+		return;
+
+	/* Bad index exists, real index doesn't?  Rename */
+	if (badindex >= 0 && realindex < 0) {
+		stmt = db_prepare_v2(db, SQL("UPDATE vars"
+					     " SET name = 'last_invoices_created_index'"
+					     " WHERE name = 'last_invoice_created_index'"));
+		db_exec_prepared_v2(stmt);
+		tal_free(stmt);
+		return;
+	}
+
+	/* Both exist.  Correct value is the higher one. */
+	if (badindex > realindex)
+		realindex = badindex;
 
-	/* Prior migration had a typo! */
-	stmt = db_prepare_v2(db, SQL("UPDATE vars"
-				     " SET name = 'last_invoices_created_index'"
+	/* Update correct one, remove bad one. */
+	db_set_intvar(db, "last_invoices_created_index", realindex);
+	stmt = db_prepare_v2(db, SQL("DELETE FROM vars"
 				     " WHERE name = 'last_invoice_created_index'"));
 	db_exec_prepared_v2(stmt);
 	tal_free(stmt);