Treat JSON null as empty value

papaparse.js

@@ -364,7 +364,7 @@
 		// Encloses a value around quotes if needed (makes a value safe for CSV insertion)
 		function safe(str, col)
 		{
-			if (typeof str === "undefined")
+			if (typeof str === "undefined" || str === null)
 				return "";
 
 			str = str.toString().replace(/"/g, '""');

tests/test-cases.js

@@ -640,5 +640,10 @@ var UNPARSE_TESTS = [
 		description: "Mismatched field counts in rows",
 		input: [['a', 'b', 'c'], ['d', 'e'], ['f']],
 		expected: 'a,b,c\r\nd,e\r\nf'
+	},
+	{
+		description: "JSON null is treated as empty value",
+		input: [{ "Col1": "a", "Col2": null, "Col3": "c" }],
+		expected: 'Col1,Col2,Col3\r\na,,c'
 	}
 ];