fix attrwrapper.pop and float.imag

src/runtime/float.cpp

@@ -1122,7 +1122,7 @@ static Box* floatConjugate(Box* b, void*) {
         raiseExcHelper(TypeError, "descriptor 'conjugate' requires a 'float' object but received a '%s'",
                        getTypeName(b));
     if (b->cls == float_cls) {
-        return b;
+        return incref(b);
     } else {
         assert(PyFloat_Check(b));
         return boxFloat(static_cast<BoxedFloat*>(b)->d);

src/runtime/types.cpp

@@ -2425,8 +2425,9 @@ public:
 
         Box* r = self->b->getattr(key);
         if (r) {
+            Py_INCREF(r);
             self->b->delattr(key, NULL);
-            return incref(r);
+            return r;
         } else {
             if (default_)
                 return incref(default_);

test/tests/float.py

@@ -69,6 +69,7 @@ print (0.5).as_integer_ratio()
 print (0.5).is_integer()
 print (1.0).is_integer()
 print 1.0.__hash__(), 1.1.__hash__(), -1.1.__hash__()
+print (0.5).conjugate(), (0.6).imag
 
 print 1.0 ** (10 ** 100)
 print (-1.0) ** (10 ** 100)