FMSLogo Code

Tighten up some of the PO tests to make sure that they print the exact expected values.

Formally thank Bob Gorman for notifying me about a bug in READWORD.

Add a hook in Help -> Examples to draw something on the main screen so that I can (later) test printing and saving as a bitmap.

Make pressing the right arrow in the commander's history box behave the same as it does in the OWL-based FMSLogo.

Add a regression test for bug #2500256, which is that SCROLLBARSET has bad error recovery logic if the max value is less than the min value.

Fix a bug where the "general MIDI" error didn't display the error-specific string to the user.

Fix a bug where the status code wasn't being propagated from gifsave_helper().

Fix bug #1475214; MIDIOPEN no longer opens MIDI mapper when given bad input.

Fix bug #1475223; MIDI procedures now throw MIDI-specific errors and no longer display dialog boxes.

Fix bug #1500676; Windowing procedures now throw windowing-specific errors and no longer display dialog boxes.

I added two new errors, one for "WINDOW already exists" and one for "WINDOW does not exist". I could have gone with more specific errors, such as "No scrollbar named NAME exists", but this would have created extra work for the localizers without much benefit to the user. If someone complains, I'll add more specific error messages.