complete: Sort --keep-order completions smaller

This should make the sort have a strict weak ordering, which rust
requires since 1.81 (or it will panic).

Note: This changes the order, but that's *fine* since the current
order is random weirdness anyway.

Fixes #10763

src/complete.rs

@@ -480,6 +480,12 @@ fn natural_compare_completions(a: &Completion, b: &Completion) -> Ordering {
         // Both completions are from a source with the --keep-order flag.
         return Ordering::Equal;
     }
+    if (a.flags).contains(CompleteFlags::DONT_SORT) {
+        return Ordering::Less;
+    }
+    if (b.flags).contains(CompleteFlags::DONT_SORT) {
+        return Ordering::Greater;
+    }
     wcsfilecmp(&a.completion, &b.completion)
 }
 

tests/checks/complete-group-order.fish

@@ -18,15 +18,15 @@ complete -c fooc -fa "kilo juliett lima"
 
 # Generate completions
 complete -C"fooc "
-# CHECK: alpha
-# CHECK: bravo
 # CHECK: india
 # CHECK: foxtrot
 # CHECK: hotel
 # CHECK: golf
 # CHECK: charlie
-# CHECK: delta
 # CHECK: echo
+# CHECK: alpha
+# CHECK: bravo
+# CHECK: delta
 # CHECK: juliett
 # CHECK: kilo
 # CHECK: lima

tests/pexpects/complete-group-order.py

@@ -43,6 +43,6 @@ expect_prompt()
 send("fooc \t")
 
 expect_re(
-    "alpha\W+india\W+hotel\W+charlie\W+echo\W+kilo\r\n"
+    "india\W+hotel\W+charlie\W+alpha\W+delta\W+kilo\r\n"
-    + "bravo\W+foxtrot\W+golf\W+delta\W+juliett\W+lima"
+    + "foxtrot\W+golf\W+echo\W+bravo\W+juliett\W+lima"
 )