Mirar, when you added the tests that infinity is always printed as "inf", it looks like you forgot to commit the fixes to sprintf that actually makes this happen...
/pike/home/marcus/Pike/7.5/src/modules/sprintf/testsuite.in:121: Test 93 (shift 0) (CRNL) failed. 1: mixed a() { return sprintf("%f",exp(65536)); } 2: mixed b() { return "inf"; } 3:
o->a(): "Inf" o->b(): "inf"
etc. There is a reason why the tests were just stringp() before.