(Or, "How do I get Alexandre to apply my patch quickly so I can build on it and it will not go stale?")
Make sure your patch applies to the current Git HEAD revisions. If a bunch of patches are committed that may affect whether your patch will apply cleanly then verify that your patch does apply! git fetch; git rebase origin is your friend!
Patches must not break building Wine or cause test failures. Adding dead code should also be avoided.
Save yourself some embarrassment and run your patched code against more than just your current test example. Experience will tell you how much effort to apply here. If there are any conformance tests for the code you're working on, run them and make sure they still pass after your patch is applied. Running tests can be done by running make test. You may need to run make testclean to undo the results of a previous test run. See the "testing" guide for more details on Wine conformance tests.