fix(rsync):Use the canonical command for alias completions.

completions-core/rsync.bash

@@ -85,7 +85,7 @@ _comp_cmd_rsync()
             # meaning before v3.2.0) contain the following unusual line in
             # --help:
             # "(-h) --help                  show this help (-h is --help only if used alone)"
-            if _comp_compgen -Rv tmp help - <<<"$("$1" --help 2>&1 | command sed -e 's/^([^)]*)//')"; then
+            if _comp_compgen -Rv tmp help - <<<"$(command rsync --help 2>&1 | command sed -e 's/^([^)]*)//')"; then
 
                 _comp_compgen -- -W '"${tmp[@]}"
                     --daemon --old-d{,irs}
@@ -106,7 +106,7 @@ _comp_cmd_rsync()
                 fi
             done
             if [[ $shell == ssh ]]; then
-                local rsync_version=$("$1" --version 2>/dev/null |
+                local rsync_version=$(command rsync --version 2>/dev/null |
                     command sed -n '1s/.*rsync *version \([0-9.]*\).*/\1/p')
                 _comp_cmd_rsync__vercomp "$rsync_version" "3.2.4"
                 if (($? == 2)); then

test/t/test_rsync.py

@@ -1,6 +1,6 @@
 import pytest
 
-from conftest import assert_bash_exec, assert_complete
+from conftest import assert_bash_exec, assert_complete, is_bash_type
 
 
 @pytest.mark.bashcomp(ignore_env=r"^[+-]_comp_cmd_scp__path_esc=")
@@ -75,6 +75,32 @@ def test_remote_path_with_spaces(self, bash):
             or completion == r"\\\ in\\\ filename.txt"
         )
 
+    def test_alias_options(self, bash):
+        """Options for a manually registered alias match the real command."""
+        if not is_bash_type(bash, "rsync"):
+            pytest.skip("Command not found")
+        assert_bash_exec(
+            bash,
+            "alias _comp_test_rsync_alias=rsync",
+        )
+        assert_bash_exec(
+            bash,
+            "complete -o nospace -F _comp_cmd_rsync _comp_test_rsync_alias",
+        )
+        try:
+            expected = assert_complete(bash, "rsync --")
+            completion = assert_complete(
+                bash,
+                "_comp_test_rsync_alias --",
+            )
+            assert completion == expected
+        finally:
+            assert_bash_exec(
+                bash,
+                "unalias _comp_test_rsync_alias; "
+                "complete -r _comp_test_rsync_alias 2>/dev/null || true",
+            )
+
     @pytest.mark.complete(r"rsync -na spaced\ ", cwd="scp")
     def test_local_path_with_spaces(self, completion):
         """This function tests xfunc _comp_xfunc_scp_compgen_local_files, which