1. Draw a text frame with the Frame Text tool.
2. Type some text into the frame. Make it short enough not to force the line to wrap.
3. With the cursor to the right of the right-most character, press and hold the space bar to insert multiple spaces.
Result: Eventually the cursor advances past the right edge of the text frame and keeps heading to the right—until you type a non-space character. Then the line wraps. Not that anyone would likely do this as part of creating a document...but it does seem anomalous. : )
(Hoping the screen-shot upload works this time.)