From bbea7da669605c5ef9c3f1d24eb7c6e810dac5b1 Mon Sep 17 00:00:00 2001
From: Tilen Gimpelj <66419530+Tiggax@users.noreply.github.com>
Date: Wed, 13 Sep 2023 13:49:55 +0200
Subject: [PATCH] Remove `select` error if same row/column is provided (#10350)

This PR is in reference to #10215.

This PR changes `select` to work even if multiple equal items were
provided.
This would previously error, but now works
```nushell
let arg = [ 1 a ]
[[a b c]; [1 2 3] [4 5 6] [7 8 9]]
| select $arg

```
# User-Facing Changes

Nothing too radical, just experience improvements. Users won't need to
pass the values through `unique` beforehand.
---
 crates/nu-command/src/filters/select.rs    | 15 +++++----------
 crates/nu-command/tests/commands/select.rs | 13 ++++++++++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/crates/nu-command/src/filters/select.rs b/crates/nu-command/src/filters/select.rs
index 9a62565dec..d06f14ca8d 100644
--- a/crates/nu-command/src/filters/select.rs
+++ b/crates/nu-command/src/filters/select.rs
@@ -214,18 +214,13 @@ fn select(
                         Vec::new(),
                     ));
                 }
-                if unique_rows.contains(val) {
-                    return Err(ShellError::GenericError(
-                        "Select can't get the same row twice".into(),
-                        "duplicated row index".into(),
-                        Some(*span),
-                        None,
-                        Vec::new(),
-                    ));
-                }
                 unique_rows.insert(*val);
             }
-            _ => new_columns.push(column),
+            _ => {
+                if !new_columns.contains(&column) {
+                    new_columns.push(column)
+                }
+            }
         };
     }
     let columns = new_columns;
diff --git a/crates/nu-command/tests/commands/select.rs b/crates/nu-command/tests/commands/select.rs
index 900a70ab0c..d44fc54391 100644
--- a/crates/nu-command/tests/commands/select.rs
+++ b/crates/nu-command/tests/commands/select.rs
@@ -218,10 +218,17 @@ fn select_failed3() {
 }
 
 #[test]
-fn select_failed4() {
-    let actual = nu!("[{a: 1 b: 10}, {a:2, b:11}] | select 0 0");
+fn select_repeated_rows() {
+    let actual = nu!("[[a b c]; [1 2 3] [4 5 6] [7 8 9]] | select 0 0 | to nuon");
 
-    assert!(actual.err.contains("Select can't get the same row twice"));
+    assert_eq!(actual.out, "[[a, b, c]; [1, 2, 3]]");
+}
+
+#[test]
+fn select_repeated_column() {
+    let actual = nu!("[[a b c]; [1 2 3] [4 5 6] [7 8 9]] | select a a | to nuon");
+
+    assert_eq!(actual.out, "[[a]; [1], [4], [7]]");
 }
 
 #[test]