show correct auto complete value for nargs option in combination with flag option

CHANGES.rst

@@ -3,7 +3,7 @@
 Version 8.2.0
 -------------
 
-Unreleased
+Released 2025-01-12
 
 -   Drop support for Python 3.7. :pr:`2588`
 -   Use modern packaging metadata with ``pyproject.toml`` instead of ``setup.cfg``.
@@ -98,6 +98,8 @@ Unreleased
 -   ``Choice`` is now generic and supports any iterable value.
     This allows you to use enums and other non-``str`` values. :pr:`2796`
     :issue:`605`
+-   show correct auto complete value for nargs option in combination with
+    flag option :issue:`2813`
 
 Version 8.1.8
 -------------

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "click"
-version = "8.2.0.dev"
+version = "8.2.0"
 description = "Composable command line interface toolkit"
 readme = "README.md"
 license = {file = "LICENSE.txt"}

src/click/shell_completion.py

@@ -525,6 +525,7 @@ def _is_incomplete_option(ctx: Context, args: list[str], param: Parameter) -> bo
 
         if _start_of_option(ctx, arg):
             last_option = arg
+            break
 
     return last_option is not None and last_option in param.opts
 

tests/test_shell_completion.py

@@ -188,6 +188,19 @@ def test_option_flag():
     assert _get_words(cli, ["--on"], "a") == ["a1", "a2"]
 
 
+def test_flag_option_with_nargs_option():
+    cli = Command(
+        "cli",
+        add_help_option=False,
+        params=[
+            Argument(["a"], type=Choice(["a1", "a2", "b"])),
+            Option(["--flag"], is_flag=True),
+            Option(["-c"], type=Choice(["p", "q"]), nargs=2),
+        ],
+    )
+    assert _get_words(cli, ["a1", "--flag", "-c"], "") == ["p", "q"]
+
+
 def test_option_custom():
     def custom(ctx, param, incomplete):
         return [incomplete.upper()]