feat(_comp__init): source system startup files earlier

Author: akinomyoga

bash_completion

@@ -3595,10 +3595,14 @@ _comp__init_collect_startup_configs()
 
     # collect startup files
     local -A startup_visited=()
-    local startup_dir startup_files
     for startup_dir in "${startup_dirs[@]}"; do
         [[ -d $startup_dir && -r $startup_dir && -x $startup_dir ]] || continue
+
+        local -a startup_files=()
         _comp_expand_glob startup_files "$startup_dir/*.bash" || continue
+
+        local -a selected_startup_files=()
+        local startup_dir
         for startup_file in "${startup_files[@]}"; do
             [[ ! -d $startup_file && -r $startup_file ]] || continue
 
@@ -3610,8 +3614,19 @@ _comp__init_collect_startup_configs()
             [[ ${startup_visited[$name]-} ]] && continue
             startup_visited[$name]=set
 
-            _comp__init_startup_configs+=("$startup_file")
+            selected_startup_files+=("$startup_file")
         done
+        ((${#selected_startup_files[@]})) || continue
+
+        # Note: bash < 4.4 has a bug that all elements are connected with
+        # ${a[@]+"${a[@]}"} when IFS does not contain whitespace.
+        local IFS=$' \t\n'
+        # Prepend the selected startup files because we want to source the
+        # system startup files earlier.
+        _comp__init_startup_configs=(
+            "${selected_startup_files[@]}"
+            ${_comp__init_startup_configs[@]+"${_comp__init_startup_configs[@]}"}
+        )
     done
 
     # collect compat completion directory definitions

test/t/unit/test_unit_init_collect_startup_configs.py

@@ -14,11 +14,11 @@ def test_count(self, bash):
     @pytest.mark.parametrize(
         "module,expected",
         [
-            ("foo", "usr:1"),
-            ("bar", "usr:2"),
-            ("baz", "usr:3"),
-            ("qux", "usr:4"),
-            ("quux", "sys:5"),
+            ("quux", "sys:1"),
+            ("foo", "usr:2"),
+            ("bar", "usr:3"),
+            ("baz", "usr:4"),
+            ("qux", "usr:5"),
         ],
     )
     def test_order(self, bash, module, expected):