public static string MakeValidName()

in src/ICSharpCode.SharpZipLib/Zip/WindowsNameTransform.cs [180:239]
45 lines of code
11 McCabe index (conditional complexity)

		public static string MakeValidName(string name, char replacement)
		{
			if (name == null)
			{
				throw new ArgumentNullException(nameof(name));
			}

			name = PathUtils.DropPathRoot(name.Replace("/", Path.DirectorySeparatorChar.ToString()));

			// Drop any leading slashes.
			while ((name.Length > 0) && (name[0] == Path.DirectorySeparatorChar))
			{
				name = name.Remove(0, 1);
			}

			// Drop any trailing slashes.
			while ((name.Length > 0) && (name[name.Length - 1] == Path.DirectorySeparatorChar))
			{
				name = name.Remove(name.Length - 1, 1);
			}

			// Convert consecutive \\ characters to \
			int index = name.IndexOf(string.Format("{0}{0}", Path.DirectorySeparatorChar), StringComparison.Ordinal);
			while (index >= 0)
			{
				name = name.Remove(index, 1);
				index = name.IndexOf(string.Format("{0}{0}", Path.DirectorySeparatorChar), StringComparison.Ordinal);
			}

			// Convert any invalid characters using the replacement one.
			index = name.IndexOfAny(InvalidEntryChars);
			if (index >= 0)
			{
				var builder = new StringBuilder(name);

				while (index >= 0)
				{
					builder[index] = replacement;

					if (index >= name.Length)
					{
						index = -1;
					}
					else
					{
						index = name.IndexOfAny(InvalidEntryChars, index + 1);
					}
				}
				name = builder.ToString();
			}

			// Check for names greater than MaxPath characters.
			// TODO: Were is CLR version of MaxPath defined?  Can't find it in Environment.
			if (name.Length > MaxPath)
			{
				throw new PathTooLongException();
			}

			return name;
		}