use messages for query responses to allow communicating error

1 files changed, 8 insertions, 5 deletions

diff --git a/doc/design/external_special_remote_protocol.mdwn b/doc/design/external_special_remote_protocol.mdwn
index 2c3fd2a4e..4d2304a89 100644
--- a/doc/design/external_special_remote_protocol.mdwn
+++ b/doc/design/external_special_remote_protocol.mdwn
@@ -38,9 +38,9 @@ The special remote can now ask git-annex for its configuration, as needed,
 and check that it's valid. git-annex responds with the configuration values
 
 	GETCONFIG directory
-	/media/usbdrive/repo
+	VALUE /media/usbdrive/repo
 	GETCONFIG automount
-	true
+	VALUE true
 
 Once the special remote is satisfied with its configuration and is
 ready to go, it tells git-annex.
@@ -169,9 +169,6 @@ avoid sending additional messages. While git-annex is in quiet mode,
 the special remote can send queries to it. Queries can not be sent at any
 other time.
 
-When it sees a query, git-annex will respond a line containing
-*only* the requested data.
-
 * `DIRHASH Key`  
   Gets a two level hash associated with a Key. Something like "abc/def".
   This is always the same for any given Key, so can be used for eg,
@@ -188,6 +185,12 @@ When it sees a query, git-annex will respond a line containing
   between them. If two repositories set different values in the state
   for a key, the one that sets it last wins.
 
+When it sees a query, git-annex will respond a VALUE message.
+The rest of the line contains the requested data.
+git-annex may also respond with an ERROR message if it did not
+understand the query. In this case, it will continue processing
+further messages.
+
 ## Simple shell example
 
 [[!format sh """