Test for missing argument.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/luarocks/lint.lua b/src/luarocks/lint.lua
index 63b549aa..61388af6 100644
--- a/src/luarocks/lint.lua
+++ b/src/luarocks/lint.lua
@@ -12,13 +12,17 @@ help_arguments = "<rockspec>"
 help = [[
 This is a utility function that checks the syntax of a rockspec.
 
-It reports success or failure if the text of a rockspec is
+It returns success or failure if the text of a rockspec is
 syntactically correct.
 ]]
 
 function run(...)
    local flags, input = util.parse_flags(...)
    
+   if not input then
+      return nil, "Argument missing, see help."
+   end
+   
    local filename = input
    if not input:match(".rockspec$") then
       local err