test_sort: Add one more test checking arbitrary precision handling

tests/by-util/test_sort.rs

@@ -1527,3 +1527,43 @@ fn test_g_misc() {
         .succeeds()
         .stdout_is(output);
 }
+
+#[test]
+// Test numbers with a large number of digits, where only the last digit is different.
+// We use scientific notation to make sure string sorting does not correctly order them.
+fn test_g_arbitrary() {
+    let input = [
+        // GNU coreutils doesn't handle those correctly as they don't fit exactly in long double
+        "3",
+        "3.000000000000000000000000000000000000000000000000000000000000000004",
+        "0.3000000000000000000000000000000000000000000000000000000000000000002e1",
+        "0.03000000000000000000000000000000000000000000000000000000000000000003e2",
+        "0.003000000000000000000000000000000000000000000000000000000000000000001e3",
+        // GNU coreutils does handle those correctly though
+        "10",
+        "10.000000000000004",
+        "1.0000000000000002e1",
+        "0.10000000000000003e2",
+        "0.010000000000000001e3",
+    ]
+    .join("\n");
+    let output = [
+        "3",
+        "0.003000000000000000000000000000000000000000000000000000000000000000001e3",
+        "0.3000000000000000000000000000000000000000000000000000000000000000002e1",
+        "0.03000000000000000000000000000000000000000000000000000000000000000003e2",
+        "3.000000000000000000000000000000000000000000000000000000000000000004",
+        "10",
+        "0.010000000000000001e3",
+        "1.0000000000000002e1",
+        "0.10000000000000003e2",
+        "10.000000000000004",
+    ]
+    .join("\n")
+        + "\n";
+    new_ucmd!()
+        .args(&["-g"])
+        .pipe_in(input)
+        .succeeds()
+        .stdout_is(output);
+}