From fb5ba01e5a551a36d0366a126630d49a31c29785 Mon Sep 17 00:00:00 2001
From: Wilma456 <wilma456@gmx.de>
Date: Fri, 23 Jun 2017 17:38:40 +0200
Subject: [PATCH] Add Checks to Colors API

---
 .../computercraft/lua/rom/apis/colors.lua     | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/main/resources/assets/computercraft/lua/rom/apis/colors.lua b/src/main/resources/assets/computercraft/lua/rom/apis/colors.lua
index fea975d16..30da8c8ea 100644
--- a/src/main/resources/assets/computercraft/lua/rom/apis/colors.lua
+++ b/src/main/resources/assets/computercraft/lua/rom/apis/colors.lua
@@ -19,32 +19,51 @@ black = 32768
 function combine( ... )
     local r = 0
     for n,c in ipairs( { ... } ) do
+        if type( c ) ~= "number" then
+            error( "bad argument #"..n.." (expected number, got " .. type( c ) .. ")", 2 )
+        end
         r = bit32.bor(r,c)
     end
     return r
 end
 
 function subtract( colors, ... )
+    if type( colors ) ~= "number" then
+        error( "bad argument #1 (expected number, got " .. type( colors ) .. ")", 2 )
+    end
     local r = colors
     for n,c in ipairs( { ... } ) do
+        if type( c ) ~= "number" then
+            error( "bad argument #"..tostring( n+1 ).." (expected number, got " .. type( c ) .. ")", 2 )
+        end
         r = bit32.band(r, bit32.bnot(c))
     end
     return r
 end
 
 function test( colors, color )
+    if type( colors ) ~= "number" then
+        error( "bad argument #1 (expected number, got " .. type( colors ) .. ")", 2 )
+    end
+    if type( color ) ~= "number" then
+        error( "bad argument #2 (expected number, got " .. type( color ) .. ")", 2 )
+    end
     return ((bit32.band(colors, color)) == color)
 end
 
 function rgb8( r, g, b )
-    if type(r) == "number" and g == nil and b == nil then
+    if type( r ) ~= "number" then
+        error( "bad argument #1 (expected number, got " .. type( r ) .. ")", 2 )
+    elseif type(r) == "number" and g == nil and b == nil then
         return bit32.band( bit32.rshift( r, 16 ), 0xFF ) / 255, bit32.band( bit32.rshift( r, 8 ), 0xFF ) / 255, bit32.band( r, 0xFF ) / 255
     elseif type(r) == "number" and type(g) == "number" and type(b) == "number" then
         return 
             bit32.lshift( bit32.band(r * 255, 0xFF), 16 ) +
             bit32.lshift( bit32.band(g * 255, 0xFF), 8 ) +
             bit32.band(b * 255, 0xFF)
-    else
-        error( "Expected 1 or 3 numbers", 2 )
+    elseif type( g ) ~= "number" then
+        error( "bad argument #2 (expected number, got " .. type( g ) .. ")", 2 )
+    elseif type( b ) ~= "number" then
+        error( "bad argument #3 (expected number, got " .. type( b ) .. ")", 2 )
     end
 end