import os
import shlex

# Taint must CLEAR when a name is rebound to a non-source value (#29).
# Neither function below may produce a finding.


def reassigned_constant():
    g = os.getenv("G")      # tainted source
    g = "safe-constant"     # rebound to a literal -> taint must clear
    os.system(g)            # must NOT be flagged


def sanitized_reassignment():
    x = input("path> ")     # tainted source
    x = shlex.quote(x)      # rebound to a non-source call -> taint must clear
    os.system(x)            # must NOT be flagged