Fix oversights in the high-level iconv wrapper

Runtime/Bindings/FFI/iconv/iconv.lua

@@ -73,9 +73,10 @@ function iconv.convert(input, inputEncoding, outputEncoding)
 	readBuffer = readBuffer or buffer.new(256)
 	writeBuffer = writeBuffer or buffer.new(256)
 
+	readBuffer:reset()
 	readBuffer:put(input)
 	local readCursor = readBuffer:ref()
-	request.input.charset = "CP949"
+	request.input.charset = inputEncoding
 	request.input.buffer = readCursor
 	request.input.length = #input
 	request.input.remaining = #input
@@ -85,7 +86,7 @@ function iconv.convert(input, inputEncoding, outputEncoding)
 
 	writeBuffer:reset()
 	local writeCursor, writeBufferCapacity = writeBuffer:reserve(maxRequiredWriteBufferSize)
-	request.output.charset = "UTF-8"
+	request.output.charset = outputEncoding
 	request.output.buffer = writeCursor
 	request.output.length = writeBufferCapacity
 	request.output.remaining = writeBufferCapacity

Tests/BDD/iconv-library.spec.lua

@@ -166,14 +166,16 @@ describe("iconv", function()
 			local input = "유저인터페이스"
 			assertFailure(function()
 				return iconv.convert(input, "INVALID_ENCODING", "UTF-8")
-			end, iconv.strerror(ffi.C.ICONV_CONVERSION_FAILED))
+				-- TBD: This is what the library returns - even though it's misleading at best (?)
+			end, iconv.strerror(ffi.C.ICONV_INCOMPLETE_INPUT))
 		end)
 
 		it("should fail if given an invalid output encoding", function()
 			local input = "유저인터페이스"
 			assertFailure(function()
-				return iconv.convert(input, "UTF-8", "INVALID_ENCODING")
-			end, iconv.strerror(ffi.C.ICONV_CONVERSION_FAILED))
+				return iconv.convert(input, "CP949", "INVALID_ENCODING")
+				-- TBD: This is what the library returns - even though it's  misleading at best (?)
+			end, iconv.strerror(ffi.C.ICONV_INCOMPLETE_INPUT))
 		end)
 
 		it("should throw if a non-string input was passed", function()
@@ -202,6 +204,16 @@ describe("iconv", function()
 				"Expected argument outputEncoding to be a string value, but received a number value instead"
 			assertThrows(convertWithInvalidOutputEncoding, expectedErrorMessage)
 		end)
+
+		it("should be able to convert multiple inputs using the same buffer", function()
+			local output, result = iconv.convert("First", "ASCII", "UTF-8")
+			assertEquals(output, "First")
+			assertEquals(result, iconv.strerror(ffi.C.ICONV_RESULT_OK))
+
+			output, result = iconv.convert("Second", "ASCII", "UTF-8")
+			assertEquals(output, "Second")
+			assertEquals(result, iconv.strerror(ffi.C.ICONV_RESULT_OK))
+		end)
 	end)
 
 	describe("strerror", function()