thunderbird, firefox: fix file conflict for native messaging hosts

On Linux, both Thunderbird and Firefox use the same directory to contain
native messaging host modules. On this platform, we have to merge both
directories with native hosts into one.

The patch introduces a separate helper module to manage native host
directory generation. Now program modules (firefox, thunderbird) declare
native hosts to initialize; while the new helper module determines
*where* and *how* to merge them on disc.

Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>

modules/misc/mozilla-messaging-hosts.nix

@@ -0,0 +1,89 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  inherit (pkgs.stdenv) isDarwin;
+
+  cfg = config.mozilla;
+
+  defaultPaths = [
+    # Link a .keep file to keep the directory around
+    (pkgs.writeTextDir "lib/mozilla/native-messaging-hosts/.keep" "")
+  ];
+
+  thunderbirdNativeMessagingHostsPath = if isDarwin then
+    "Library/Mozilla/NativeMessagingHosts"
+  else
+    ".mozilla/native-messaging-hosts";
+
+  firefoxNativeMessagingHostsPath = if isDarwin then
+    "Library/Application Support/Mozilla/NativeMessagingHosts"
+  else
+    ".mozilla/native-messaging-hosts";
+in {
+  meta.maintainers =
+    [ maintainers.booxter maintainers.rycee hm.maintainers.bricked ];
+
+  options.mozilla = {
+    firefoxNativeMessagingHosts = mkOption {
+      internal = true;
+      type = with types; listOf package;
+      default = [ ];
+      description = ''
+        List of Firefox native messaging hosts to configure.
+      '';
+    };
+
+    thunderbirdNativeMessagingHosts = mkOption {
+      internal = true;
+      type = with types; listOf package;
+      default = [ ];
+      description = ''
+        List of Thunderbird native messaging hosts to configure.
+      '';
+    };
+  };
+
+  config = mkIf (cfg.firefoxNativeMessagingHosts != [ ]
+    || cfg.thunderbirdNativeMessagingHosts != [ ]) {
+      home.file = if isDarwin then
+        let
+          firefoxNativeMessagingHostsJoined = pkgs.symlinkJoin {
+            name = "ff-native-messaging-hosts";
+            paths = defaultPaths ++ cfg.firefoxNativeMessagingHosts;
+          };
+          thunderbirdNativeMessagingHostsJoined = pkgs.symlinkJoin {
+            name = "th-native-messaging-hosts";
+            paths = defaultPaths ++ cfg.thunderbirdNativeMessagingHosts;
+          };
+        in {
+          "${thunderbirdNativeMessagingHostsPath}" = {
+            source =
+              "${thunderbirdNativeMessagingHostsJoined}/lib/mozilla/native-messaging-hosts";
+            recursive = true;
+          };
+
+          "${firefoxNativeMessagingHostsPath}" = {
+            source =
+              "${firefoxNativeMessagingHostsJoined}/lib/mozilla/native-messaging-hosts";
+            recursive = true;
+          };
+        }
+      else
+        let
+          nativeMessagingHostsJoined = pkgs.symlinkJoin {
+            name = "mozilla-native-messaging-hosts";
+            # on Linux, the directory is shared between Firefox and Thunderbird; merge both into one
+            paths = defaultPaths ++ cfg.firefoxNativeMessagingHosts
+              ++ cfg.thunderbirdNativeMessagingHosts;
+          };
+        in {
+          "${firefoxNativeMessagingHostsPath}" = {
+            source =
+              "${nativeMessagingHostsJoined}/lib/mozilla/native-messaging-hosts";
+            recursive = true;
+          };
+        };
+    };
+}

modules/modules.nix

@@ -30,6 +30,7 @@ let
     ./misc/fontconfig.nix
     ./misc/gtk.nix
     ./misc/lib.nix
+    ./misc/mozilla-messaging-hosts.nix
     ./misc/news.nix
     ./misc/nixgl.nix
     ./misc/numlock.nix

modules/programs/firefox/mkFirefoxModule.nix

@@ -30,23 +30,6 @@ let
   profilesPath =
     if isDarwin then "${cfg.configPath}/Profiles" else cfg.configPath;
 
-  nativeMessagingHostsPath = if isDarwin then
-    "${cfg.vendorPath}/NativeMessagingHosts"
-  else
-    "${cfg.vendorPath}/native-messaging-hosts";
-
-  nativeMessagingHostsJoined = pkgs.symlinkJoin {
-    name = "ff_native-messaging-hosts";
-    paths = [
-      # Link a .keep file to keep the directory around
-      (pkgs.writeTextDir "lib/mozilla/native-messaging-hosts/.keep" "")
-      # Link package configured native messaging hosts (entire browser actually)
-      cfg.finalPackage
-    ]
-    # Link user configured native messaging hosts
-      ++ cfg.nativeMessagingHosts;
-  };
-
   # The extensions path shared by all profiles; will not be supported
   # by future browser versions.
   extensionPath = "extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}";
@@ -864,16 +847,14 @@ in {
 
     home.packages = lib.optional (cfg.finalPackage != null) cfg.finalPackage;
 
+    mozilla.firefoxNativeMessagingHosts = [
+      cfg.finalPackage # package configured native messaging hosts (entire browser actually)
+    ] ++ cfg.nativeMessagingHosts; # user configured native messaging hosts
+
     home.file = mkMerge ([{
       "${cfg.configPath}/profiles.ini" =
         mkIf (cfg.profiles != { }) { text = profilesIni; };
-    }] ++ optional (cfg.vendorPath != null) {
-      "${nativeMessagingHostsPath}" = {
-        source =
-          "${nativeMessagingHostsJoined}/lib/mozilla/native-messaging-hosts";
-        recursive = true;
-      };
-    } ++ flip mapAttrsToList cfg.profiles (_: profile:
+    }] ++ flip mapAttrsToList cfg.profiles (_: profile:
       # Merge the regular profile settings with extension settings
       mkMerge ([{
         "${profilesPath}/${profile.path}/.keep".text = "";

modules/programs/thunderbird.nix

@@ -136,24 +136,6 @@ let
     '') prefs)}
     ${extraPrefs}
   '';
-
-  nativeMessagingHostsPath = if isDarwin then
-    "${cfg.vendorPath}/NativeMessagingHosts"
-  else
-    "${cfg.vendorPath}/native-messaging-hosts";
-
-  nativeMessagingHostsJoined = pkgs.symlinkJoin {
-    name = "th_native-messaging-hosts";
-    paths = [
-      # Link a .keep file to keep the directory around
-      (pkgs.writeTextDir "lib/mozilla/native-messaging-hosts/.keep" "")
-      # Link package configured native messaging hosts (entire mail app actually)
-      cfg.package
-    ]
-    # Link user configured native messaging hosts
-      ++ cfg.nativeMessagingHosts;
-  };
-
 in {
   meta.maintainers = with hm.maintainers; [ d-dervishi jkarlson ];
 
@@ -176,20 +158,7 @@ in {
         description = "profile version, set null for nix-darwin";
       };
 
-      vendorPath = mkOption {
-        internal = true;
-        type = with types; nullOr str;
-        # Thunderbird doesn't look in `Application Support` on macOS for user
-        # config (in contrast to global settings that are the same for Firefox
-        # and Thunderbird):
-        # https://developer.thunderbird.net/add-ons/mailextensions/supported-webextension-api
-        default = if isDarwin then "Library/Mozilla" else ".mozilla";
-        example = ".mozilla";
-        description =
-          "Directory containing the native messaging hosts directory.";
-      };
-
-      nativeMessagingHosts = optionalAttrs (cfg.vendorPath != null) (mkOption {
+      nativeMessagingHosts = mkOption {
         visible = true;
         type = types.listOf types.package;
         default = [ ];
@@ -197,7 +166,7 @@ in {
           Additional packages containing native messaging hosts that should be
           made available to Thunderbird extensions.
         '';
-      });
+      };
 
       profiles = mkOption {
         type = with types;
@@ -441,16 +410,14 @@ in {
       ++ optional (any (p: p.withExternalGnupg) (attrValues cfg.profiles))
       pkgs.gpgme;
 
+    mozilla.thunderbirdNativeMessagingHosts = [
+      cfg.package # package configured native messaging hosts (entire mail app actually)
+    ] ++ cfg.nativeMessagingHosts; # user configured native messaging hosts
+
     home.file = mkMerge ([{
       "${thunderbirdConfigPath}/profiles.ini" =
         mkIf (cfg.profiles != { }) { text = generators.toINI { } profilesIni; };
-    }] ++ optional (cfg.vendorPath != null) {
-      "${nativeMessagingHostsPath}" = {
-        source =
-          "${nativeMessagingHostsJoined}/lib/mozilla/native-messaging-hosts";
-        recursive = true;
-      };
-    } ++ flip mapAttrsToList cfg.profiles (name: profile: {
+    }] ++ flip mapAttrsToList cfg.profiles (name: profile: {
       "${thunderbirdProfilesPath}/${name}/chrome/userChrome.css" =
         mkIf (profile.userChrome != "") { text = profile.userChrome; };
 

tests/modules/programs/thunderbird/thunderbird.nix

@@ -37,14 +37,18 @@
     };
   };
 
+  # Confirm that both Firefox and Thunderbird can be configured at the same time.
+  programs.firefox = { enable = true; };
+
   programs.thunderbird = {
     enable = true;
 
     # Disable warning so that platforms' behavior is the same
     darwinSetupWarning = false;
 
-    # Darwin doesn't support wrapped Thunderbird, using unwrapped instead
-    package = realPkgs.thunderbird-unwrapped;
+    # Darwin doesn't support wrapped Thunderbird, using unwrapped instead;
+    # using -latest- because ESR is currently broken on Darwin
+    package = realPkgs.thunderbird-latest-unwrapped;
 
     profiles = {
       first = {