feat: add _comp_compgen_split

Co-authored-by: Ville Skyttä <ville.skytta@iki.fi>

bash_completion

@@ -633,6 +633,46 @@ _comp_compgen_set()
     eval -- "$_var${_append:++}=(\"\$@\")"
 }
 
+# Simply split the text and generate completions.  This function should be used
+# instead of `_comp_compgen -- -W "$(command)"`, which is vulnerable because
+# option -W evaluates the shell expansions included in the option argument.
+# Options:
+#   -F sep  Specify the separators. The default is $' \t\n'
+#   -l      The same as -F $'\n'
+#   -X arg  The same as the compgen option -X.
+#   -S arg  The same as the compgen option -S.
+#   -P arg  The same as the compgen option -P.
+#   -o arg  The same as the compgen option -o.
+# @param $1 String to split
+# @since 2.12
+_comp_compgen_split()
+{
+    local _ifs=$' \t\n'
+    local -a _compgen_options=()
+
+    local OPTIND=1 OPTARG="" OPTERR=0 _opt
+    while getopts ':lF:X:S:P:o:' _opt "$@"; do
+        case $_opt in
+            l) _ifs=$'\n' ;;
+            F) _ifs=$OPTARG ;;
+            [XSPo]) _compgen_options+=("-$_opt" "$OPTARG") ;;
+            *)
+                printf 'bash_completion: usage: %s [-l|-F sep] [--] str\n' "$FUNCNAME" >&2
+                return 2
+                ;;
+        esac
+    done
+    shift "$((OPTIND - 1))"
+    if (($# != 1)); then
+        printf 'bash_completion: %s: unexpected number of arguments.\n' "$FUNCNAME" >&2
+        printf 'usage: %s [-l|-F sep] [--] str' "$FUNCNAME" >&2
+        return 2
+    fi
+
+    local _split_input=$1
+    _comp_compgen -F "$_ifs" -- "${_compgen_options[@]}" -W '$_split_input'
+}
+
 # Check if the argument looks like a path.
 # @param $1 thing to check
 # @return True (0) if it does, False (> 0) otherwise

test/t/unit/test_unit_compgen_split.py

@@ -0,0 +1,102 @@
+import pytest
+
+from conftest import assert_bash_exec
+
+
+@pytest.mark.bashcomp(cmd=None)
+class TestUtilCompgenSplit:
+    @pytest.fixture
+    def functions(self, bash):
+        assert_bash_exec(
+            bash,
+            "_comp__test_dump() { ((${#arr[@]})) && printf '<%s>' \"${arr[@]}\"; echo; }",
+        )
+        assert_bash_exec(
+            bash,
+            '_comp__test_compgen() { local -a arr=(00); _comp_compgen -v arr "$@"; _comp__test_dump; }',
+        )
+
+        assert_bash_exec(
+            bash,
+            "_comp__test_cmd1() { echo foo bar; echo baz; }",
+        )
+        assert_bash_exec(
+            bash,
+            '_comp__test_attack() { echo "\\$(echo should_not_run >&2)"; }',
+        )
+
+    def test_1_basic(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo><bar><baz>"
+
+    def test_2_attack(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -- "$(_comp__test_attack)"',
+            want_output=True,
+        )
+        assert output.strip() == "<$(echo><should_not_run><>&2)>"
+
+    def test_3_sep1(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -l -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo bar><baz>"
+
+    def test_3_sep2(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            "_comp__test_compgen split -F $'b\\n' -- \"$(_comp__test_cmd1)\"",
+            want_output=True,
+        )
+        assert output.strip() == "<foo ><ar><az>"
+
+    def test_4_optionX(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -X bar -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo><baz>"
+
+    def test_4_optionS(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -S .txt -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo.txt><bar.txt><baz.txt>"
+
+    def test_4_optionP(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -P /tmp/ -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "</tmp/foo></tmp/bar></tmp/baz>"
+
+    def test_4_optionPS(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -P [ -S ] -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<[foo]><[bar]><[baz]>"
+
+    def test_5_empty(self, bash, functions):
+        output = assert_bash_exec(
+            bash, '_comp__test_compgen split -- ""', want_output=True
+        )
+        assert output.strip() == ""
+
+    def test_5_empty2(self, bash, functions):
+        output = assert_bash_exec(
+            bash, '_comp__test_compgen split -- " "', want_output=True
+        )
+        assert output.strip() == ""