From 3e6dc542010182c3c4baa401bb7be11d071c2dbd Mon Sep 17 00:00:00 2001
From: mpeterv <petjamelnik@yandex.ru>
Date: Thu, 20 Feb 2014 12:48:51 +0400
Subject: [PATCH] If an option with a default value is underused, invoke it
 more

---
 spec/default_spec.lua |  9 +++++++++
 src/argparse.lua      | 13 ++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/spec/default_spec.lua b/spec/default_spec.lua
index 777cc1a..770d59e 100644
--- a/spec/default_spec.lua
+++ b/spec/default_spec.lua
@@ -42,6 +42,15 @@ describe("tests related to default values", function()
          assert.same({foo = "bar"}, args)
       end)
 
+      it("handles underused option with default value correctly", function()
+         local parser = Parser()
+         parser:option "-o" "--output"
+            :count(1)
+            :default "a.out"
+         local args = parser:parse{}
+         assert.same({output = "a.out"}, args)
+      end)
+
       it("doesn't use default if option is not invoked", function()
          local parser = Parser()
          parser:option("-f", "--foo", {
diff --git a/src/argparse.lua b/src/argparse.lua
index 66e9694..d649a19 100644
--- a/src/argparse.lua
+++ b/src/argparse.lua
@@ -761,9 +761,16 @@ function Parser:_parse(args, errhandler)
    end
 
    for _, option in ipairs(options) do
-      assert_(invocations[option] >= option._mincount,
-         "option '%s' must be used at least %d times", option._name, option._mincount
-      )
+      if invocations[option] < option._mincount then
+         if option._default then
+            while invocations[option] < option._mincount do
+               invoke(option)
+               close(option)
+            end
+         else
+            error_("option '%s' must be used at least %d times", option._name, option._mincount)
+         end
+      end
    end
 
    for _, callback in ipairs(com_callbacks) do