safe in $ENV{TERM} for taint checkings.
p4raw-id: //depot/perl@18261
PL_tainted = was_tainted;
if (t < e && isALNUM(*t))
t++;
- while (t < e && (isALNUM(*t) || *t == '-' || *t == ':'))
+ while (t < e && (isALNUM(*t) || strchr("-_.+", *t)))
t++;
if (t < e) {
TAINT;