Special character handling in URLs
==================================

Bazaar allows locations to be specified in multiple ways, either:

 * Fully qualified URLs

 * File system paths, relative or absolute

Internally bzr treats all locations as URLs. For any file system paths
that are specified it will automatically determine the appropriate URL
representation, and escape special characters where necessary.

There are a few characters which have special meaning in URLs and need careful
handling to avoid ambiguities. Characters can be escaped with a % and a hex
value in URLs. Any non-ASCII characters in a file path will automatically be
urlencoded when the path is converted to a URL.

URLs represent non-ASCII characters in an encoding defined by the server, but
usually UTF-8.  The % escapes should be of the UTF-8 bytes.  Bazaar tries to be
generous in what it accepts as a URL and to print them in a way that
will be readable.

For example, if you have a directory named '/tmp/%2False' these are all valid
ways of accessing the content (0x2F, or 47, is the ASCII code for forward slash)::

  cd /tmp
  bzr log /tmp/%2False
  bzr log %2False
  bzr log file:///tmp/%252False
  bzr log file://localhost/tmp/%252False
  bzr log file:%252False

These are valid but do not refer to the same file::

  bzr log file:///tmp/%2False (refers to a file called /tmp/\/alse)
  bzr log %252False (refers to a file called /tmp/%252False)

Comma also has special meaning in URLs, because it denotes `segment parameters`_

_`segment parameters`: http://www.ietf.org/rfc/rfc3986.txt (section 3.3)

Comma is also special in any file system paths that are specified. To use a literal
comma in a file system path, specify a URL and URL encode the comma::

  bzr log foo,branch=bla # path "foo" with the segment parameter "branch" set to "bla"
  bzr log file:foo%2Cbranch=bla # path "foo,branch=bla"
  bzr log file:foo,branch=bla # path "foo" with segment parameter "branch" set to "bla"