Fix doctests related to singular: make them compatible with newer releases of Singular.

src/sage/interfaces/singular.py

@@ -626,7 +626,7 @@ def eval(self, x, allow_semicolon=True, strip=True, **kwds):
             sage: o = s.hilb()
             ...// dimension (affine) = 0
             // degree (affine)  = 8
-            // ** right side is not a datum, assignment ignored
+            // ** right side is not a datum, assignment...ignored
             ...
 
         rather than ignored
@@ -1763,7 +1763,7 @@ def sage_poly(self, R=None, kcache=None):
             -4.00000000000000*z^3 - 27.0000000000000
             sage: Rx.<x> = RR[]
             sage: Rx("x + 7.5")._singular_().sage_poly()
-            x + 7.50000
+            x + 7.50000...
             sage: Rx("x + 7.5")._singular_().sage_poly(Rx)
             x + 7.50000000000000
 

src/sage/libs/singular/function.pyx

@@ -1262,31 +1262,6 @@ cdef class SingularFunction(SageObject):
             sage: with open(out) as f:
             ....:     'is no standard basis' in f.read()
             False
-
-
-        TESTS:
-
-        We show that the interface recovers gracefully from errors::
-
-            sage: P.<e,d,c,b,a> = PolynomialRing(QQ,5,order='lex')
-            sage: I = sage.rings.ideal.Cyclic(P)
-
-            sage: triangL = sage.libs.singular.function_factory.ff.triang__lib.triangL
-            sage: _ = triangL(I)
-            Traceback (most recent call last):
-            ...
-            RuntimeError: error in Singular function call 'triangL':
-            The input is no groebner basis.
-            leaving triang.lib::triangL (0)
-
-        Flush any stray output -- see :issue:`28622`::
-
-            sage: sys.stdout.flush()
-            ...
-
-            sage: G= Ideal(I.groebner_basis())
-            sage: triangL(G,attributes={G:{'isSB':1}})
-            [[e + d + c + b + a, ...]]
         """
         global dummy_ring
 
@@ -1351,9 +1326,7 @@ EXAMPLES::
     sage: I = Ideal(Ideal(f1,f2).groebner_basis()[::-1])
     sage: triangL(I, attributes={I:{'isSB':1}})
     [[x2^4 + 4*x2^3 - 6*x2^2 - 20*x2 + 5, 8*x1 - x2^3 + x2^2 + 13*x2 - 5],
-     [x2, x1^2],
-     [x2, x1^2],
-     [x2, x1^2]]
+     [x2, x1^2]...
 
 """ % (self._name)
         from sage.interfaces.singular import get_docstring

src/sage/rings/polynomial/multi_polynomial_ideal.py

@@ -1004,9 +1004,7 @@ def triangular_decomposition(self, algorithm=None, singular=None):
             sage: f2 = 1/2*((x1^2 + 2*x1 + 1)*x2^2 + 2*(x1^2 + x1)*x2 - 4*x1^2)
             sage: I = Ideal(f1,f2)
             sage: I.triangular_decomposition()
-            [Ideal (x2, x1^2) of Multivariate Polynomial Ring in x1, x2 over Rational Field,
-             Ideal (x2, x1^2) of Multivariate Polynomial Ring in x1, x2 over Rational Field,
-             Ideal (x2, x1^2) of Multivariate Polynomial Ring in x1, x2 over Rational Field,
+            [Ideal (x2, x1^2) of Multivariate Polynomial Ring in x1, x2 over Rational Field...
              Ideal (x2^4 + 4*x2^3 - 6*x2^2 - 20*x2 + 5, 8*x1 - x2^3 + x2^2 + 13*x2 - 5)
               of Multivariate Polynomial Ring in x1, x2 over Rational Field]
 

src/sage/rings/polynomial/polynomial_ring_constructor.py

@@ -521,7 +521,7 @@ def PolynomialRing(base_ring, *args, **kwds):
         //        block   2 : ordering C
         sage: print(singular(R))
         polynomial ring, over a field, global ordering
-        // coefficients: Float() considered as a field
+        // coefficients: Float(...) considered as a field
         // number of vars : 1
         //        block   1 : ordering dp
         //                  : names    x

src/sage/rings/polynomial/polynomial_singular_interface.py

@@ -202,7 +202,7 @@ def _singular_(self, singular=None):
             sage: R.<x,y> = PolynomialRing(RealField(100))                              # needs sage.rings.real_mpfr
             sage: singular(R)                                                           # needs sage.libs.singular sage.rings.real_mpfr
             polynomial ring, over a field, global ordering
-            // coefficients: Float()...
+            // coefficients: Float(...
             // number of vars : 2
             //        block   1 : ordering dp
             //                  : names    x y

src/sage/sandpiles/sandpile.py

@@ -2533,14 +2533,21 @@ def _set_resolution(self):
         """
         # get the resolution in singular form
         res = self.ideal()._singular_().mres(0)
+        len_res = len(res)
+        sing = res.parent()
+        # remove trailing zero in the resolution
+        found_zero = False
+        if sing.size(res[len_res]) == 0:
+            len_res -= 1
+            found_zero = True
         # compute the betti numbers
-        # self._betti = [1] + [len(res[i])
-        #        for i in range(1,len(res)-2)]
         self._betti = [1] + [len(x) for x in res]
+        if found_zero:
+            self._betti = self._betti[:-1]
         # convert the resolution to a list of Sage poly matrices
         result = []
         zero = self._ring.gens()[0] * 0
-        for i in range(1, len(res) + 1):
+        for i in range(1, len_res + 1):
             syz_mat = []
             new = [res[i][j] for j in range(1, int(res[i].size()) + 1)]
             for j in range(self._betti[i]):

src/sage/schemes/generic/algebraic_scheme.py

@@ -1134,15 +1134,9 @@ def irreducible_components(self):
 
             sage: PP.<x,y,z,w,v> = ProjectiveSpace(4, QQ)
             sage: V = PP.subscheme((x^2 - y^2 - z^2) * (w^5 - 2*v^2*z^3) * w * (v^3 - x^2*z))
-            sage: V.irreducible_components()                                            # needs sage.libs.singular
-            [Closed subscheme of Projective Space of dimension 4 over Rational Field defined by:
-               w,
-             Closed subscheme of Projective Space of dimension 4 over Rational Field defined by:
-               x^2 - y^2 - z^2,
-             Closed subscheme of Projective Space of dimension 4 over Rational Field defined by:
-               x^2*z - v^3,
-             Closed subscheme of Projective Space of dimension 4 over Rational Field defined by:
-               w^5 - 2*z^3*v^2]
+            sage: Vc=V.irreducible_components()                                      # needs sage.libs.singular
+            sage: len(Vc)==4 and all(PP.subscheme(t) in  Vc for t in [w, -w^5 + 2*z^3*v^2, -x^2*z + v^3, -x^2 + y^2 + z^2])                                                 # needs sage.libs.singular
+            True
 
         We verify that the irrelevant ideal is not accidentally returned
         (see :issue:`6920`)::