V3057. Function receives an odd argument.

Feb. 20, 2016

The analyzer detected a possible error that has to do with passing a suspicious value as an argument to a function.

Consider the following examples:

Invalid characters in a path

string GetLogPath(string root)
{
  return System.IO.Path.Combine(root, @"\my|folder\log.txt");
}

A path containing invalid character '|' is passed to function 'Combine()'. It will result in an 'ArgumentException'.

The fixed version:

string GetLogPath(string root)
{
  return System.IO.Path.Combine(root, @"\my\folder\log.txt"); 
}

Invalid index

var pos = mask.IndexOf('\0');
if (pos != 0)
    asciiname = mask.Substring(0, pos);

'IndexOf()' returns the position of a specified argument. If the argument is not found, the function returns the value '-1'. And passing a negative index to function 'Substring()' results in an 'ArgumentOutOfRangeException'.

The fixed version:

var pos = mask.IndexOf('\0');
if (pos > 0)
    asciiname = mask.Substring(0, pos);

Suspicious argument to format function

string.Format(mask, 1, 2, mask);

The 'string.Format()' function replaces one or more format items in a specified string. An attempt to write the same string into the format string is treated as suspicious by the analyzer.

According to Common Weakness Enumeration, potential errors found by using this diagnostic are classified as CWE-628.

You can look at examples of errors detected by the V3057 diagnostic.