From 9e23fbe01787d164605ee2ad40d4cda6e0a3e81a Mon Sep 17 00:00:00 2001
From: vera-rubin <322284620+vera-rubin@users.noreply.github.com>
Date: Sat, 17 Oct 2026 12:20:52 +0000
Subject: [PATCH] Fix argsort for views with nonzero data offsets

---
 include/xtensor/misc/xsort.hpp |  2 +-
 test/test_xsort.cpp            | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/xtensor/misc/xsort.hpp b/include/xtensor/misc/xsort.hpp
index 196ec45cd..1de56f240 100644
--- a/include/xtensor/misc/xsort.hpp
+++ b/include/xtensor/misc/xsort.hpp
@@ -101,7 +101,7 @@ namespace xt
 
             const auto begin1 = e1.data();
             const auto end1 = begin1 + n_iters * secondary_stride1;
-            const auto begin2 = e2.data();
+            const auto begin2 = e2.data() + e2.data_offset();
             const auto end2 = begin2 + n_iters * secondary_stride2;
             auto iter1 = begin1;
             auto iter2 = begin2;
diff --git a/test/test_xsort.cpp b/test/test_xsort.cpp
index bbe928d4d..7a53918f3 100644
--- a/test/test_xsort.cpp
+++ b/test/test_xsort.cpp
@@ -17,6 +17,7 @@
 #include "xtensor/io/xio.hpp"
 #include "xtensor/misc/xsort.hpp"
 #include "xtensor/views/xslice.hpp"
+#include "xtensor/views/xstrided_view.hpp"
 #include "xtensor/views/xview.hpp"
 
 #include "test_common_macros.hpp"
@@ -70,6 +71,27 @@ namespace xt
         }
     }
 
+    TEST(xsort, argsort_view_offset)
+    {
+        xarray<int, layout_type::row_major> a = {{1, 2, 3}, {3, 2, 1}};
+        auto row = view(a, range(1, 2), all());
+        auto strided_row = strided_view(a, {range(1, 2), all()});
+        xarray<std::size_t> expected_row = {{2, 1, 0}};
+
+        xarray<int, layout_type::column_major> b = {{1, 3}, {2, 2}, {3, 1}};
+        auto column = view(b, all(), range(1, 2));
+        auto strided_column = strided_view(b, {all(), range(1, 2)});
+        xtensor<std::size_t, 2> expected_column = {{2}, {1}, {0}};
+
+        for (auto method : {sorting_method::quick, sorting_method::stable})
+        {
+            EXPECT_EQ(expected_row, argsort(row, 1, method));
+            EXPECT_EQ(expected_row, argsort(strided_row, 1, method));
+            EXPECT_EQ(expected_column, argsort(column, 0, method));
+            EXPECT_EQ(expected_column, argsort(strided_column, 0, method));
+        }
+    }
+
     TEST(xsort, argsort_zero_stride)
     {
         {