Sort: Various fixes and performance improvements (#2057)

* Various fixes and performance improvements

* fix a typo

Co-authored-by: Michael Debertol <michael.debertol@gmail.com>

Co-authored-by: Sylvestre Ledru <sledru@mozilla.com>
Co-authored-by: Michael Debertol <michael.debertol@gmail.com>

tests/by-util/test_sort.rs

@@ -1,5 +1,31 @@
 use crate::common::util::*;
 
+fn test_helper(file_name: &str, args: &str) {
+    new_ucmd!()
+        .arg(args)
+        .arg(format!("{}.txt", file_name))
+        .succeeds()
+        .stdout_is_fixture(format!("{}.expected", file_name));
+}
+
+#[test]
+fn test_multiple_decimals_general() {
+    new_ucmd!()
+        .arg("-g")
+        .arg("multiple_decimals_general.txt")
+        .succeeds()
+        .stdout_is("\n\n\n\n\n\n\n\nCARAvan\n-2028789030\n-896689\n-8.90880\n-1\n-.05\n000\n00000001\n1\n1.040000000\n1.444\n1.58590\n8.013\n45\n46.89\n576,446.88800000\n576,446.890\n               4567.\n4567.1\n4567.34\n\t\t\t\t\t\t\t\t\t\t4567..457\n\t\t\t\t37800\n\t\t\t\t\t\t45670.89079.098\n\t\t\t\t\t\t45670.89079.1\n4798908.340000000000\n4798908.45\n4798908.8909800\n");
+}
+
+#[test]
+fn test_multiple_decimals_numeric() {
+    new_ucmd!()
+        .arg("-n")
+        .arg("multiple_decimals_numeric.txt")
+        .succeeds()
+        .stdout_is("-2028789030\n-896689\n-8.90880\n-1\n-.05\n\n\n\n\n\n\n\n\n000\nCARAvan\n00000001\n1\n1.040000000\n1.444\n1.58590\n8.013\n45\n46.89\n               4567.\n4567.1\n4567.34\n\t\t\t\t\t\t\t\t\t\t4567..457\n\t\t\t\t37800\n\t\t\t\t\t\t45670.89079.098\n\t\t\t\t\t\t45670.89079.1\n576,446.88800000\n576,446.890\n4798908.340000000000\n4798908.45\n4798908.8909800\n");
+}
+
 #[test]
 fn test_check_zero_terminated_failure() {
     new_ucmd!()
@@ -44,6 +70,21 @@ fn test_random_shuffle_contains_all_lines() {
     assert_eq!(result_sorted, expected);
 }
 
+#[test]
+fn test_random_shuffle_two_runs_not_the_same() {
+    // check to verify that two random shuffles are not equal; this has the
+    // potential to fail in the very unlikely event that the random order is the same
+    // as the starting order, or if both random sorts end up having the same order.
+    const FILE: &'static str = "default_unsorted_ints.expected";
+    let (at, _ucmd) = at_and_ucmd!();
+    let result = new_ucmd!().arg("-R").arg(FILE).run().stdout;
+    let expected = at.read(FILE);
+    let unexpected = new_ucmd!().arg("-R").arg(FILE).run().stdout;
+
+    assert_ne!(result, expected);
+    assert_ne!(result, unexpected);
+}
+
 #[test]
 fn test_random_shuffle_contains_two_runs_not_the_same() {
     // check to verify that two random shuffles are not equal; this has the
@@ -355,11 +396,3 @@ fn test_check_silent() {
         .fails()
         .stdout_is("");
 }
-
-fn test_helper(file_name: &str, args: &str) {
-    new_ucmd!()
-        .arg(args)
-        .arg(format!("{}{}", file_name, ".txt"))
-        .succeeds()
-        .stdout_is_fixture(format!("{}{}", file_name, ".expected"));
-}

tests/fixtures/sort/mixed_floats_ints_chars_numeric_unique_reverse_stable.expected

@@ -0,0 +1,20 @@
+4798908.8909800
+4798908.45
+4798908.340000000000
+576,446.890
+576,446.88800000
+				37800
+               4567.
+46.89
+45
+8.013
+1.58590
+1.444
+1.040000000
+1
+
+-.05
+-1
+-8.90880
+-896689
+-2028789030

tests/fixtures/sort/multiple_decimals.expected

@@ -0,0 +1,33 @@
+-2028789030
+-896689
+-8.90880
+-1
+-.05
+
+
+
+
+
+
+
+
+000
+CARAvan
+00000001
+1
+1.040000000
+1.444
+1.58590
+8.013
+45
+46.89
+										4567..457
+               4567.
+4567.1
+4567.34
+				37800
+576,446.88800000
+576,446.890
+4798908.340000000000
+4798908.45
+4798908.8909800

tests/fixtures/sort/multiple_decimals_general.txt

@@ -0,0 +1,35 @@
+576,446.890
+576,446.88800000
+
+4567.1
+										4567..457
+						45670.89079.1
+						45670.89079.098
+4567.34
+               4567.
+45
+46.89
+-1
+1
+00000001
+4798908.340000000000
+4798908.45
+4798908.8909800
+
+
+				37800
+
+-2028789030
+-896689
+CARAvan
+
+-8.90880
+-.05
+1.444
+1.58590
+1.040000000
+
+8.013
+
+000
+

tests/fixtures/sort/multiple_decimals_numeric.txt

@@ -0,0 +1,35 @@
+576,446.890
+576,446.88800000
+
+4567.1
+										4567..457
+						45670.89079.1
+						45670.89079.098
+4567.34
+               4567.
+45
+46.89
+-1
+1
+00000001
+4798908.340000000000
+4798908.45
+4798908.8909800
+
+
+				37800
+
+-2028789030
+-896689
+CARAvan
+
+-8.90880
+-.05
+1.444
+1.58590
+1.040000000
+
+8.013
+
+000
+