System.Globalization.CultureTableRecord.ReescapeWin32String C# (CSharp) Method

        static private String ReescapeWin32String(String str)
        {
            // If we don't have data, then don't try anything
            if (str == null)
                return null;
            
            StringBuilder result = null;

            bool inQuote = false;
            for (int i = 0; i < str.Length; i++)
            {
                // Look for quote
                if (str[i] == '\'')
                {
                    // Already in quote?
                    if (inQuote)
                    {
                        // See another single quote.  Is this '' of 'fred''s' or '''', or is it an ending quote?
                        if (i + 1 < str.Length && str[i+1] == '\'')
                        {
                            // Found another ', so we have ''.  Need to add \' instead.
                            // 1st make sure we have our stringbuilder
                            if (result == null)
                                result = new StringBuilder(str, 0, i, str.Length * 2);

                            // Append a \' and keep going (so we don't turn off quote mode)
                            result.Append("\\'");
                            i++;
                            continue;
                        }

                        // Turning off quote mode, fall through to add it
                        inQuote = false;
                    }
                    else
                    {
                        // Found beginning quote, fall through to add it
                        inQuote = true;
                    }
                }
                // Is there a single \ character?
                else if (str[i] == '\\')
                {
                    // Found a \, need to change it to \\
                    // 1st make sure we have our stringbuilder
                    if (result == null)
                        result = new StringBuilder(str, 0, i, str.Length * 2);

                    // Append our \\ to the string & continue
                    result.Append("\\\\");
                    continue;
                }

                // If we have a builder we need to add our character
                if (result != null)
                    result.Append(str[i]);
            }

            // Unchanged string? , just return input string
            if (result == null)
                return str;

            // String changed, need to use the builder
            return result.ToString();
        }