From 1f4d2acf82be712a5b6dc4efb4349823d758c08a Mon Sep 17 00:00:00 2001
From: user202729 <25191436+user202729@users.noreply.github.com>
Date: Sat, 4 Oct 2025 12:38:26 +0700
Subject: [PATCH] Workaround for linbox charpoly/minpoly issues, take 2

---
 src/sage/matrix/matrix_integer_dense.pyx  | 2 +-
 src/sage/matrix/matrix_integer_sparse.pyx | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/sage/matrix/matrix_integer_dense.pyx b/src/sage/matrix/matrix_integer_dense.pyx
index d582393e565..a1ad92fa58b 100644
--- a/src/sage/matrix/matrix_integer_dense.pyx
+++ b/src/sage/matrix/matrix_integer_dense.pyx
@@ -1416,7 +1416,7 @@ cdef class Matrix_integer_dense(Matrix_dense):
                 sig_on()
                 linbox_fmpz_mat_charpoly(g._poly, self._matrix)
                 sig_off()
-                if g.lc() == 1:
+                if g.lc() == 1 and g.degree() == self._nrows:
                     break
         elif algorithm == 'generic':
             g = Matrix_dense.charpoly(self, var)
diff --git a/src/sage/matrix/matrix_integer_sparse.pyx b/src/sage/matrix/matrix_integer_sparse.pyx
index 9c68b951907..dc961d53f44 100644
--- a/src/sage/matrix/matrix_integer_sparse.pyx
+++ b/src/sage/matrix/matrix_integer_sparse.pyx
@@ -912,7 +912,7 @@ cdef class Matrix_integer_sparse(Matrix_sparse):
                 fmpz_poly_set_coeff_mpz(g._poly, i, tmp)
             _fmpz_poly_set_length(g._poly, p.size())
 
-            if g.lc() == 1:
+            if g.lc() == 1 and g.degree() == self._nrows:
                 break
 
         del M