From 7db2997bc3cec68a78c7884c558d14992e05ee16 Mon Sep 17 00:00:00 2001
From: Alex Szpakowski <slime73@gmail.com>
Date: Tue, 26 Jan 2016 22:19:35 -0400
Subject: [PATCH] Improved the error messages caused when invalid or missing
 arguments are given to ImageData and SoundData methods.

---
 src/modules/image/wrap_ImageData.lua | 27 +++++++++++++++++++--------
 src/modules/sound/wrap_SoundData.lua |  5 +++++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/modules/image/wrap_ImageData.lua b/src/modules/image/wrap_ImageData.lua
index 21ecafb82..22fbc451b 100644
--- a/src/modules/image/wrap_ImageData.lua
+++ b/src/modules/image/wrap_ImageData.lua
@@ -42,12 +42,12 @@ function ImageData:mapPixel(func, ix, iy, iw, ih)
 	iw = iw or idw
 	ih = ih or idh
 
-	if type(ix) ~= "number" then error("Invalid argument #2 to ImageData:mapPixel (expected number)", 2) end
-	if type(iy) ~= "number" then error("Invalid argument #3 to ImageData:mapPixel (expected number)", 2) end
-	if type(iw) ~= "number" then error("Invalid argument #4 to ImageData:mapPixel (expected number)", 2) end
-	if type(ih) ~= "number" then error("Invalid argument #5 to ImageData:mapPixel (expected number)", 2) end
+	if type(ix) ~= "number" then error("bad argument #2 to ImageData:mapPixel (expected number)", 2) end
+	if type(iy) ~= "number" then error("bad argument #3 to ImageData:mapPixel (expected number)", 2) end
+	if type(iw) ~= "number" then error("bad argument #4 to ImageData:mapPixel (expected number)", 2) end
+	if type(ih) ~= "number" then error("bad argument #5 to ImageData:mapPixel (expected number)", 2) end
 
-	if type(func) ~= "function" then error("Invalid argument #1 to ImageData:mapPixel (expected function)", 2) end
+	if type(func) ~= "function" then error("bad argument #1 to ImageData:mapPixel (expected function)", 2) end
 	if not (inside(ix, iy, idw, idh) and inside(ix+iw-1, iy+ih-1, idw, idh)) then error("Invalid rectangle dimensions", 2) end
 
 	-- performAtomic and mapPixelUnsafe have Lua-C API and FFI versions.
@@ -141,6 +141,9 @@ function ImageData:_mapPixelUnsafe(func, ix, iy, iw, ih)
 end
 
 function ImageData:getPixel(x, y)
+	if type(x) ~= "number" then error("bad argument #1 to ImageData:getPixel (expected number)", 2) end
+	if type(y) ~= "number" then error("bad argument #2 to ImageData:getPixel (expected number)", 2) end
+
 	local p = objectcache[self]
 	if not inside(x, y, p.width, p.height) then error("Attempt to get out-of-range pixel!", 2) end
 
@@ -154,15 +157,23 @@ end
 
 local temppixel = ffi.new("ImageData_Pixel")
 
-function ImageData:setPixel(x, y, r, g, b, a)	
-	local p = objectcache[self]
-	if not inside(x, y, p.width, p.height) then error("Attempt to set out-of-range pixel!", 2) end
+function ImageData:setPixel(x, y, r, g, b, a)
+	if type(x) ~= "number" then error("bad argument #1 to ImageData:setPixel (expected number)", 2) end
+	if type(y) ~= "number" then error("bad argument #2 to ImageData:setPixel (expected number)", 2) end
 
 	if type(r) == "table" then
 		local t = r
 		r, g, b, a = t[1], t[2], t[3], t[4]
 	end
 
+	if type(r) ~= "number" then error("bad red color component argument to ImageData:setPixel (expected number)", 2) end
+	if type(g) ~= "number" then error("bad green color component argument to ImageData:setPixel (expected number)", 2) end
+	if type(b) ~= "number" then error("bad blue color component argument to ImageData:setPixel (expected number)", 2) end
+	if a ~= nil and type(a) ~= "number" then error("bad alpha color component argument to ImageData:setPixel (expected number)", 2) end
+
+	local p = objectcache[self]
+	if not inside(x, y, p.width, p.height) then error("Attempt to set out-of-range pixel!", 2) end
+
 	temppixel.r = r
 	temppixel.g = g
 	temppixel.b = b
diff --git a/src/modules/sound/wrap_SoundData.lua b/src/modules/sound/wrap_SoundData.lua
index 0a9d0500b..803a9a2d1 100644
--- a/src/modules/sound/wrap_SoundData.lua
+++ b/src/modules/sound/wrap_SoundData.lua
@@ -75,6 +75,8 @@ local objectcache = setmetatable({}, {
 -- Overwrite existing functions with new FFI versions.
 
 function SoundData:getSample(i)
+	if type(i) ~= "number" then error("bad argument #1 to SoundData:getSample (expected number)", 2) end
+
 	local p = objectcache[self]
 
 	if not (i >= 0 and i < p.size/p.bytedepth) then
@@ -91,6 +93,9 @@ function SoundData:getSample(i)
 end
 
 function SoundData:setSample(i, sample)
+	if type(i) ~= "number" then error("bad argument #1 to SoundData:setSample (expected number)", 2) end
+	if type(sample) ~= "number" then error("bad argument #2 to SoundData:setSample (expected number)", 2) end
+
 	local p = objectcache[self]
 
 	if not (i >= 0 and i < p.size/p.bytedepth) then