MP3424 Boost question

My question is regarding what the boost regulator will do if the input voltage approaches or exceeds the boost output voltage. Will the boost regulator regulate the output voltage, pass the input voltage through, or malfunction?

looks like it might be OK the line regulation graph in the datasheet shows it regulates at 5V with Vin of 5.5. Maybe they cut it off just before it all goes haywire? This is a good question for a demo board. The internal mosfet does work slightly differently from a discrete mosfet in that the IC has access to the “body” and can therefore block the body diode path.