1 files changed, 12 insertions, 7 deletions

diff --git a/src/luarocks/unpack.lua b/src/luarocks/unpack.lua
index 70c116fd..95762a2c 100644
--- a/src/luarocks/unpack.lua
+++ b/src/luarocks/unpack.lua
@@ -10,11 +10,13 @@ local build = require("luarocks.build")
 local dir = require("luarocks.dir")
 
 help_summary = "Unpack the contents of a rock."
-help_arguments = "{<rock>|<name> [<version>]}"
+help_arguments = "[--force] {<rock>|<name> [<version>]}"
 help = [[
 Unpacks the contents of a rock in a newly created directory.
 Argument may be a rock file, or the name of a rock in a rocks server.
 In the latter case, the app version may be given as a second argument.
+
+--force   Unpack files even if the output directory already exists.
 ]]
 
 --- Load a rockspec file to the given directory, fetches the source
@@ -88,7 +90,7 @@ end
 -- @param file string: A rockspec or .rock URL.
 -- @return boolean or (nil, string): true if successful or nil followed
 -- by an error message.
-local function run_unpacker(file)
+local function run_unpacker(file, force)
    assert(type(file) == "string")
    
    local base_name = dir.base_name(file)
@@ -100,12 +102,15 @@ local function run_unpacker(file)
    if not extension then
       return nil, file.." does not seem to be a valid filename."
    end
-   
-   if (fs.exists(dir_name)) then
+
+   local exists = fs.exists(dir_name)
+   if exists and not force then
       return nil, "Directory "..dir_name.." already exists."
    end
-   local ok, err = fs.make_dir(dir_name)
-   if not ok then return nil, err end
+   if not exists then
+      local ok, err = fs.make_dir(dir_name)
+      if not ok then return nil, err end
+   end
    local rollback = util.schedule_function(fs.delete, fs.absolute_name(dir_name))
 
    local rockspec, err
@@ -149,7 +154,7 @@ function run(...)
    end
 
    if name:match(".*%.rock") or name:match(".*%.rockspec") then
-      return run_unpacker(name)
+      return run_unpacker(name, flags["force"])
    else
       local search = require("luarocks.search")
       return search.act_on_src_or_rockspec(run_unpacker, name, version)