printf "%c" format specifier doesn't work in batch mode

[lgritz]

color C = 0.5;
printf("C = %c\n", C);

works in single point mode, not in batch mode. Changing to %g works for both.

[lgritz]

Um... maybe OSL doesn't support %c and I'm thinking of RSL?

Oof, so perhaps the revision is:

• oslc and apparently the single-shade back end are tolerant of unknown format specifiers and just roll with it, as if it were %s. They should at least warn?
• The batched back end prints wrong when unknown format specifiers are used. Should it be tolerant and just treat is like %s?
• Some of the examples in our docs still say %c or %p, even though the description of the printf function itself does not say it supports those.

[lgritz]

I know I'm yelling at the wind right now, but I wasted hours today chasing a bug long after I'd actually fixed it, because the example shader I wrote to verify it used %c and was printing the wrong thing in batch mode while I continued to hunt for a way that batch mode was doing something very wrong that was unrelated to printf itself. Computers are fun!