xdg-desktop-entries: adjust to API changes

The `makeDesktopItem` function changed in a backwards incompatible way
in

    0c713dbed4

This commit updates the module accordingly.

Fixes #2767

modules/misc/xdg-desktop-entries.nix

@@ -4,6 +4,10 @@ with lib;
 
 let
   desktopEntry = {
+    imports = [
+      (mkRemovedOptionModule [ "extraConfig" ]
+        "The `extraConfig` option of `xdg.desktopEntries` has been removed following a change in Nixpkgs.")
+    ];
     options = {
       # Since this module uses the nixpkgs/pkgs/build-support/make-desktopitem function,
       # our options and defaults follow its parameters, with the following exceptions:
@@ -13,13 +17,9 @@ let
       # `name` on makeDesktopItem is controlled by this module's key in the attrset.
       # This is the file's filename excluding ".desktop".
 
-      # `extraEntries` on makeDesktopItem is controlled by `extraConfig`,
-      # and `extraDesktopEntries` by `settings`,
+      # `extraConfig` on makeDesktopItem is controlled by `settings`,
       # to match what's commonly used by other home manager modules.
 
-      # `mimeType` and `categories` on makeDesktopItem ask for a string in the format "one;two;three;",
-      # for usability's sake we ask for a list of strings.
-
       # Descriptions are taken from the desktop entry spec:
       # https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#recognized-keys
 
@@ -31,7 +31,7 @@ let
 
       exec = mkOption {
         description = "Program to execute, possibly with arguments.";
-        type = types.str;
+        type = types.nullOr types.str;
       };
 
       icon = mkOption {
@@ -103,15 +103,6 @@ let
         default = null;
       };
 
-      extraConfig = mkOption {
-        description = ''
-          Extra configuration. Will be appended to the end of the file and 
-          may thus contain extra sections.
-        '';
-        type = types.lines;
-        default = "";
-      };
-
       settings = mkOption {
         type = types.attrsOf types.string;
         description = ''
@@ -132,11 +123,19 @@ let
         description = "Whether to validate the generated desktop file.";
         default = true;
       };
+
+      # Required for the assertions
+      # TODO: Remove me once `mkRemovedOptionModule` works correctly with submodules
+      assertions = mkOption {
+        type = types.listOf types.unspecified;
+        default = [ ];
+        visible = false;
+        internal = true;
+      };
     };
   };
 
   #formatting helpers
-  ifNotNull = a: a': if a == null then null else a';
   semicolonList = list:
     (concatStringsSep ";" list) + ";"; # requires trailing semicolon
 
@@ -148,11 +147,9 @@ let
         type exec icon comment terminal genericName startupNotify noDisplay
         prefersNonDefaultGPU;
       desktopName = config.name;
-      mimeType = ifNotNull config.mimeType (semicolonList config.mimeType);
-      categories =
-        ifNotNull config.categories (semicolonList config.categories);
-      extraEntries = config.extraConfig;
-      extraDesktopEntries = config.settings;
+      mimeTypes = optionals (config.mimeType != null) config.mimeType;
+      categories = optionals (config.categories != null) config.categories;
+      extraConfig = config.settings;
     };
 in {
   meta.maintainers = [ hm.maintainers.cwyc ];
@@ -182,7 +179,7 @@ in {
   config = mkIf (config.xdg.desktopEntries != { }) {
     assertions = [
       (hm.assertions.assertPlatform "xdg.desktopEntries" pkgs platforms.linux)
-    ];
+    ] ++ flatten (catAttrs "assertions" (attrValues config.xdg.desktopEntries));
 
     home.packages = (map hiPrio # we need hiPrio to override existing entries
       (attrsets.mapAttrsToList makeFile config.xdg.desktopEntries));

tests/modules/misc/xdg/desktop-entries.nix

@@ -48,6 +48,13 @@ with lib;
       })
     ];
 
+    test.asserts.assertions.expected =
+      let currentFile = toString ./desktop-entries.nix;
+      in [''
+        The option definition `extraConfig' in `${currentFile}' no longer has any effect; please remove it.
+        The `extraConfig` option of `xdg.desktopEntries` has been removed following a change in Nixpkgs.
+      ''];
+
     nmt.script = ''
       assertFileExists home-path/share/applications/full.desktop
       assertFileExists home-path/share/applications/min.desktop

tests/modules/misc/xdg/desktop-full-expected.desktop

@@ -1,18 +1,16 @@
 [Desktop Entry]
-Categories=Network;WebBrowser;
+Categories=Network;WebBrowser
 Comment=My Application
 DBusActivatable=false
 Exec=test --option
 GenericName=Web Browser
 Icon=test
 Keywords=calc;math
-MimeType=text/html;text/xml;
+MimeType=text/html;text/xml
 Name=Test
 NoDisplay=false
 PrefersNonDefaultGPU=false
 StartupNotify=false
 Terminal=true
 Type=Application
-[X-ExtraSection]
-Exec=foo -o
-
+Version=1.4

tests/modules/misc/xdg/desktop-min-expected.desktop

@@ -3,3 +3,4 @@ Exec=test --option
 Name=Test
 Terminal=false
 Type=Application
+Version=1.4