[PATCH v5 06/16] Add documentation for the 'bidi-import' capability of remote-helpers

[Florian Achleitner <florian.achleitner.2.6.31@gmail.com>]

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-remote-helpers.txt |   21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index f5836e4..5faa48e 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -98,6 +98,20 @@ advertised with this capability must cover all refs reported by
 the list command.  If no 'refspec' capability is advertised,
 there is an implied `refspec *:*`.
 
+'bidi-import'::
+	The fast-import commands 'cat-blob' and 'ls' can be used by remote-helpers
+    to retrieve information about blobs and trees that already exist in
+    fast-import's memory. This requires a channel from fast-import to the
+    remote-helper.
+    If it is advertised in addition to "import", git establishes a pipe from
+	fast-import to the remote-helper's stdin.
+	It follows that git and fast-import are both connected to the
+	remote-helper's stdin. Because git can send multiple commands to
+	the remote-helper it is required that helpers that use 'bidi-import'
+	buffer all 'import' commands of a batch before sending data to fast-import.
+    This is to prevent mixing commands and fast-import responses on the
+    helper's stdin.
+
 Capabilities for Pushing
 ~~~~~~~~~~~~~~~~~~~~~~~~
 'connect'::
@@ -286,7 +300,12 @@ terminated with a blank line. For each batch of 'import', the remote
 helper should produce a fast-import stream terminated by a 'done'
 command.
 +
-Supported if the helper has the "import" capability.
+Note that if the 'bidi-import' capability is used the complete batch
+sequence has to be buffered before starting to send data to fast-import
+to prevent mixing of commands and fast-import responses on the helper's
+stdin.
++
+Supported if the helper has the 'import' capability.
 
 'connect' <service>::
 	Connects to given service. Standard input and standard output
-- 
1.7.9.5