Issue #27539: Fix unnormalised Fraction.__pow__ result for negative exponent and base. Thanks Vedran Čačić.

1 files changed, 5 insertions, 1 deletions

diff --git a/Lib/fractions.py b/Lib/fractions.py
index 60b0728807..9aabab3e3b 100644
--- a/Lib/fractions.py
+++ b/Lib/fractions.py
@@ -484,10 +484,14 @@ class Fraction(numbers.Rational):
                     return Fraction(a._numerator ** power,
                                     a._denominator ** power,
                                     _normalize=False)
-                else:
+                elif a._numerator >= 0:
                     return Fraction(a._denominator ** -power,
                                     a._numerator ** -power,
                                     _normalize=False)
+                else:
+                    return Fraction((-a._denominator) ** -power,
+                                    (-a._numerator) ** -power,
+                                    _normalize=False)
             else:
                 # A fractional power will generally produce an
                 # irrational number.