> the same place as suspicion of the "be lenient in what you accept" IETF principle No. It's fine (arguably desireable, but reasonable people might disagree) f

> the same place as suspicion of the "be lenient in what you accept" IETF principle No. It's fine (arguably desireable, but reasonable people might disagree) for implementations that encounter undefined behaviour to terminate execution immediately, especially if it's with a error message. The problem is when implementations silently willfully misinterpret what they accept, particularly in ways that cause (not "expose"; reading from a null pointer and discarding the value (for example) isn't) security vulnerablities.