wrapNeovim: symlink treesitter grammars in the wrapper

pkgs/applications/editors/neovim/utils.nix

@@ -343,7 +343,9 @@ let
 
           nativeBuildInputs = [ toNvimTreesitterGrammar ];
 
-          passthru = grammar.passthru or { };
+          passthru = grammar.passthru or { } // {
+            isTreesitterGrammar = true;
+          };
 
           meta = {
             platforms = lib.platforms.all;

pkgs/applications/editors/vim/plugins/nvim-treesitter/overrides.nix

@@ -21,7 +21,10 @@ let
     vimUtils.toVimPlugin (
       runCommand "nvim-treesitter-queries-${language}"
         {
-          passthru = { inherit language; };
+          passthru = {
+            inherit language;
+            isTreesitterQuery = true;
+          };
           meta.description = "Queries for ${language} from nvim-treesitter";
         }
         ''
@@ -94,12 +97,7 @@ let
       ];
     in
     self.nvim-treesitter.overrideAttrs {
-      passthru.dependencies = [
-        (symlinkJoin {
-          name = "nvim-treesitter-grammars";
-          paths = grammarPlugins ++ queryPlugins;
-        })
-      ];
+      passthru.dependencies = grammarPlugins ++ queryPlugins;
     };
 
   withAllGrammars = withPlugins (_: allGrammars);

pkgs/applications/editors/vim/plugins/utils/vim-utils.nix

@@ -5,6 +5,7 @@
   vim,
   vimPlugins,
   buildEnv,
+  symlinkJoin,
   writeText,
   runCommand,
   makeWrapper,
@@ -200,12 +201,26 @@ let
           # and can simply pass `null`.
           depsOfOptionalPlugins = lib.subtractLists opt (findDependenciesRecursively opt);
           startWithDeps = findDependenciesRecursively start;
-          allPlugins = lib.unique (startWithDeps ++ depsOfOptionalPlugins);
+          allPluginsAndGrammars = lib.unique (startWithDeps ++ depsOfOptionalPlugins);
+
           allPython3Dependencies =
             ps: lib.flatten (map (plugin: (plugin.python3Dependencies or (_: [ ])) ps) allPlugins);
           python3Env = python3.withPackages allPython3Dependencies;
 
-          packdirStart = vimFarm "pack/${packageName}/start" "packdir-start" allPlugins;
+          partitionGrammars = lib.partition (
+            p: p.isTreesitterGrammar or false || p.isTreesitterQuery or false
+          );
+          allPluginsAndGrammarsPartitioned = partitionGrammars allPluginsAndGrammars;
+          allPlugins = allPluginsAndGrammarsPartitioned.wrong;
+          allGrammars = allPluginsAndGrammarsPartitioned.right;
+          allGrammarsSymlinked = symlinkJoin {
+            name = "nvim-treesitter-grammars";
+            paths = allGrammars;
+          };
+
+          packdirStart = vimFarm "pack/${packageName}/start" "packdir-start" (
+            if allGrammars != [ ] then allPlugins ++ [ allGrammarsSymlinked ] else allPlugins
+          );
           packdirOpt = vimFarm "pack/${packageName}/opt" "packdir-opt" opt;
           # Assemble all python3 dependencies into a single `site-packages` to avoid doing recursive dependency collection
           # for each plugin.