krb5 commit: Document the double-colon behavior of DIR ccaches

[Greg Hudson]

https://github.com/krb5/krb5/commit/5ba6e02a7b96ddd15dde01db0f9aff3d65773a8e
commit 5ba6e02a7b96ddd15dde01db0f9aff3d65773a8e
Author: Robbie Harwood <rharwood at redhat.com>
Date:   Wed Mar 6 18:01:50 2019 -0500

    Document the double-colon behavior of DIR ccaches
    
    ticket: 8789 (new)
    tags: pullup
    target_version: 1.17-next

 doc/basic/ccache_def.rst |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/doc/basic/ccache_def.rst b/doc/basic/ccache_def.rst
index d147f0d..53542ad 100644
--- a/doc/basic/ccache_def.rst
+++ b/doc/basic/ccache_def.rst
@@ -51,6 +51,13 @@ library.
    requirement is for parent directory to exist and the current
    process must have permissions to create the directory if it does
    not exist. See :ref:`col_ccache` for details.  New in release 1.10.
+   The following residual forms are supported:
+
+   * DIR:dirname
+   * DIR::dirpath/filename - a single cache within the directory
+
+   Switching to a ccache of the latter type causes it to become the
+   primary for the directory.
 
 #. **FILE** caches are the simplest and most portable. A simple flat
    file format is used to store one credential after another.  This is