comment

Cython/Compiler/ExprNodes.py

@@ -6325,7 +6325,7 @@ static CYTHON_INLINE int __Pyx_PyUnicode_Equals(PyObject* s1, PyObject* s2, int
 """,
 impl="""
 static CYTHON_INLINE int __Pyx_PyUnicode_Equals(PyObject* s1, PyObject* s2, int equals) {
-    if (s1 == s2) {   /* as done by PyObject_RichCompareBool() */
+    if (s1 == s2) {   /* as done by PyObject_RichCompareBool(); also catches the (interned) empty string */
         return (equals == Py_EQ);
     } else if (PyUnicode_CheckExact(s1) & PyUnicode_CheckExact(s2)) {
         if (PyUnicode_GET_SIZE(s1) != PyUnicode_GET_SIZE(s2)) {