From c652b64a262184d5c7c0cdc003dc52635d4aa0d7 Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Tue, 14 Apr 2020 04:49:17 +0200
Subject: [PATCH] lib/options: Relax showOption quoting

https://github.com/NixOS/nixpkgs/commit/124cccbe3b63122733e02e41e45a383ec48752fd
broke the build of NixOS manual.

It does not make sense to be as strict as with attributes since we
are not limited by the CLI's inability to handle numbers.
Placeholders should not be quoted either as they are not part of Nix
syntax but a meta-level construct.
---
 lib/options.nix | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/lib/options.nix b/lib/options.nix
index a53b8c9f264c..7407905131b5 100644
--- a/lib/options.nix
+++ b/lib/options.nix
@@ -192,8 +192,21 @@ rec {
      Example:
        (showOption ["foo" "bar" "baz"]) == "foo.bar.baz"
        (showOption ["foo" "bar.baz" "tux"]) == "foo.\"bar.baz\".tux"
+
+     Placeholders will not be quoted as they are not actual values:
+       (showOption ["foo" "*" "bar"]) == "foo.*.bar"
+       (showOption ["foo" "<name>" "bar"]) == "foo.<name>.bar"
+
+     Unlike attributes, options can also start with numbers:
+       (showOption ["windowManager" "2bwm" "enable"]) == "windowManager.2bwm.enable"
   */
-  showOption = parts: concatMapStringsSep "." escapeNixIdentifier parts;
+  showOption = parts:
+    let
+      escapeOptionPart = part:
+        if part == "*" || builtins.match "<.+>" part != null || builtins.match "[a-zA-Z0-9_][a-zA-Z0-9_'-]+" part != null
+        then part
+        else escapeNixIdentifier part;
+    in concatMapStringsSep "." escapeOptionPart parts;
   showFiles = files: concatStringsSep " and " (map (f: "`${f}'") files);
   unknownModule = "<unknown-file>";