Add general improvements to the fs module

3 files changed, 25 insertions, 10 deletions

diff --git a/src/luarocks/fs/lua.lua b/src/luarocks/fs/lua.lua
index 373dcbdd..9da3875b 100644
--- a/src/luarocks/fs/lua.lua
+++ b/src/luarocks/fs/lua.lua
@@ -464,9 +464,13 @@ end
 --- Internal implementation function for fs.dir.
 -- Yields a filename on each iteration.
 -- @param at string: directory to list
--- @return nil
+-- @return nil or (nil and string): an error message on failure 
 function fs_lua.dir_iterator(at)
-   for file in lfs.dir(at) do
+   local pok, iter, arg = pcall(lfs.dir, at)
+   if not pok then
+      return nil, iter
+   end
+   for file in iter, arg do
       if file ~= "." and file ~= ".." then
          coroutine.yield(file)
       end
@@ -479,7 +483,11 @@ end
 -- @param prefix string: Auxiliary prefix string to form pathname.
 -- @param result table: Array of strings where results are collected.
 local function recursive_find(cwd, prefix, result)
-   for file in lfs.dir(cwd) do
+   local pok, iter, arg = pcall(lfs.dir, cwd)
+   if not pok then
+      return nil
+   end
+   for file in iter, arg do
       if file ~= "." and file ~= ".." then
          local item = prefix .. file
          table.insert(result, item)
@@ -502,9 +510,6 @@ function fs_lua.find(at)
       at = fs.current_dir()
    end
    at = dir.normalize(at)
-   if not fs.is_dir(at) then
-      return {}
-   end
    local result = {}
    recursive_find(at, "", result)
    return result
diff --git a/src/luarocks/fs/tools.lua b/src/luarocks/fs/tools.lua
index 0cfdc9f7..d2dc08ae 100644
--- a/src/luarocks/fs/tools.lua
+++ b/src/luarocks/fs/tools.lua
@@ -82,7 +82,12 @@ end
 -- Allows leaving a directory (e.g. for deleting it) in
 -- a crossplatform way.
 function tools.change_dir_to_root()
+   local curr_dir = fs.current_dir()
+   if not curr_dir or not fs.is_dir(curr_dir) then
+      return false
+   end
    table.insert(dir_stack, "/")
+   return true
 end
 
 --- Change working directory to the previous in the directory stack.
@@ -113,7 +118,7 @@ end
 -- @param at string: directory to list
 -- @return nil
 function tools.dir_iterator(at)
-   local pipe = io.popen(fs.command_at(at, fs.Q(vars.LS)))
+   local pipe = io.popen(fs.command_at(at, fs.Q(vars.LS), true))
    for file in pipe:lines() do
       if file ~= "." and file ~= ".." then
          coroutine.yield(file)
diff --git a/src/luarocks/fs/win32/tools.lua b/src/luarocks/fs/win32/tools.lua
index c267b316..de3d9031 100644
--- a/src/luarocks/fs/win32/tools.lua
+++ b/src/luarocks/fs/win32/tools.lua
@@ -13,10 +13,15 @@ local vars = setmetatable({}, { __index = function(_,k) return cfg.variables[k]
 --- Adds prefix to command to make it run from a directory.
 -- @param directory string: Path to a directory.
 -- @param cmd string: A command-line string.
+-- @param exit_on_error bool: Exits immediately if entering the directory failed.
 -- @return string: The command-line with prefix.
-function tools.command_at(directory, cmd)
+function tools.command_at(directory, cmd, exit_on_error)
    local drive = directory:match("^([A-Za-z]:)")
-   cmd = "cd " .. fs.Q(directory) .. " & " .. cmd
+   local op = " & "
+   if exit_on_error then
+      op = " && "
+   end
+   local cmd = "cd " .. fs.Q(directory) .. op .. cmd
    if drive then
       cmd = drive .. " & " .. cmd
    end
@@ -113,7 +118,7 @@ function tools.find(at)
       return {}
    end
    local result = {}
-   local pipe = io.popen(fs.command_at(at, fs.quiet_stderr(fs.Q(vars.FIND))))
+   local pipe = io.popen(fs.command_at(at, fs.quiet_stderr(fs.Q(vars.FIND)), true))
    for file in pipe:lines() do
       -- Windows find is a bit different
       local first_two = file:sub(1,2)