vim-utils: fix dependency graph (#140118)

* neovim.tests: ensure the graph is pulled

We'll change the plugin name to ensure the plugin is correctly pulled by
vim-plug config generation.
* neovim.tests: ensure nvim exit with error
* Revert "fix: remove trailing '/.' from vim-plug plugin paths"

The root cause if fixed by
761b2c6ff3 (diff-e4b94db9201d58bd9410739dddf92bef74e0b5f5e596c804a84ee7c580ae3f71R9)

This reverts commit d9d1a11aed.

pkgs/applications/editors/neovim/tests.nix

@@ -87,7 +87,7 @@ rec {
   nvim_with_plug = neovim.override {
     extraName = "-with-plug";
     configure.plug.plugins = with pkgs.vimPlugins; [
-      base16-vim
+      (base16-vim.overrideAttrs(old: { pname = old.pname + "-unique-for-tests-please-dont-use"; }))
     ];
     configure.customRC = ''
       color base16-tomorrow-night
@@ -97,7 +97,7 @@ rec {
 
   run_nvim_with_plug = runTest nvim_with_plug ''
     export HOME=$TMPDIR
-    ${nvim_with_plug}/bin/nvim -i NONE -c 'color base16-tomorrow-night'  +quit!
+    ${nvim_with_plug}/bin/nvim -i NONE -c 'color base16-tomorrow-night'  +quit! -e
   '';
 
 

pkgs/misc/vim-plugins/vim-utils.nix

@@ -292,14 +292,12 @@ let
 
       /* vim-plug is an extremely popular vim plugin manager.
       */
-      /* Remove repeated "/." suffixes from a path */
-      stripDots = path: lib.head (builtins.split "(/\\.)*$" path);
       plugImpl =
       (''
         source ${vimPlugins.vim-plug.rtp}/plug.vim
         silent! call plug#begin('/dev/null')
 
-        '' + (lib.concatMapStringsSep "\n" (pkg: "Plug '${stripDots pkg.rtp}'") plug.plugins) + ''
+        '' + (lib.concatMapStringsSep "\n" (pkg: "Plug '${pkg.rtp}'") plug.plugins) + ''
 
         call plug#end()
       '');