fix(checkhealth): module not found when `&rtp` has nested paths #32988

Problem: `:checkhealth` fail to find the module when `&rtp` have nested
paths.

Solution: find in order all existed `&rtp/lua` path rather than `&rtp`
to ensure prefix exist before trim `&rtp`.

In this case one module can be searched out from two different
`&rtp/lua`, we use the first `&rtp/lua` contain the module (like how
require() works).

1 files changed, 11 insertions, 7 deletions

diff --git a/runtime/lua/vim/health.lua b/runtime/lua/vim/health.lua
index 75cbfdef4a..c790779d51 100644
--- a/runtime/lua/vim/health.lua
+++ b/runtime/lua/vim/health.lua
@@ -109,7 +109,7 @@ local s_output = {} ---@type string[]
 
 -- From a path return a list [{name}, {func}, {type}] representing a healthcheck
 local function filepath_to_healthcheck(path)
-  path = vim.fs.normalize(path)
+  path = vim.fs.abspath(vim.fs.normalize(path))
   local name --- @type string
   local func --- @type string
   local filetype --- @type string
@@ -118,13 +118,17 @@ local function filepath_to_healthcheck(path)
     func = 'health#' .. name .. '#check'
     filetype = 'v'
   else
-    local rtp = vim
-      .iter(vim.api.nvim_list_runtime_paths())
-      :map(vim.fs.normalize)
-      :find(function(rtp0)
-        return vim.fs.relpath(rtp0, path)
+    local rtp_lua = vim
+      .iter(vim.api.nvim_get_runtime_file('lua/', true))
+      :map(function(rtp_lua)
+        return vim.fs.abspath(vim.fs.normalize(rtp_lua))
       end)
-    local subpath = path:gsub('^' .. vim.pesc(rtp .. '/lua/'), '')
+      :find(function(rtp_lua)
+        return vim.fs.relpath(rtp_lua, path)
+      end)
+    -- "/path/to/rtp/lua/foo/bar/health.lua" => "foo/bar/health.lua"
+    -- "/another/rtp/lua/baz/health/init.lua" => "baz/health/init.lua"
+    local subpath = path:gsub('^' .. vim.pesc(rtp_lua), ''):gsub('^/+', '')
     if vim.fs.basename(subpath) == 'health.lua' then
       -- */health.lua
       name = vim.fs.dirname(subpath)