src/sage/quivers/algebra_elements.pyx: Fix handling of 0 elements in …

…multiplication
sagemath · Mar 9, 2024 · 90d480e · 90d480e
1 parent 2bd14d6
commit 90d480e
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/sage/quivers/algebra_elements.pyx b/src/sage/quivers/algebra_elements.pyx
@@ -1196,6 +1196,8 @@ cdef class PathAlgebraElement(RingElement):
             sage: z*3
             3*a + 6*b + 9*e_2
         """
+        if self.data == NULL:
+            return self
         cdef path_homog_poly_t * out = homog_poly_scale(self.data, right)
         cdef path_homog_poly_t * outnxt
         if out.poly.nterms == 0:
@@ -1226,6 +1228,8 @@ cdef class PathAlgebraElement(RingElement):
             sage: 3*z
             3*a + 6*b + 9*e_2
         """
+        if self.data == NULL:
+            return self
         cdef path_homog_poly_t * out = homog_poly_scale(self.data, left)
         cdef path_homog_poly_t * outnxt
         if out.poly.nterms == 0:
@@ -1312,7 +1316,11 @@ cdef class PathAlgebraElement(RingElement):
             sage: pA^5 == sage_eval(repr(pF^5), A.gens_dict())
             True
         """
+        if self.data == NULL:
+            return self
         cdef PathAlgebraElement right = other
+        if right.data == NULL:
+            return right
         cdef path_homog_poly_t *H1 = self.data
         cdef path_homog_poly_t *H2
         cdef path_term_t *T2