Make PatchAddEdit complain and not modify entry if fields are invalid instead of just filling in zeros. Fixes issue 4291.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@7672 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/StringUtil.cpp

@@ -130,6 +130,9 @@ bool TryParse(const std::string &str, u32 *const output)
 	if (!endptr || *endptr)
 		return false;
 
+	if (value == ULONG_MAX && errno == ERANGE)
+		return false;
+
 	*output = value;
 	return true;
 }