fix init default description reversion

init: Fix a reversion in the last release that prevented automatically
generating and setting a description for the repository.

Seemed best to factor out uuidDescMapRaw that does not
have the default mempty descrition behavior.

I don't much like that behavior, but I know things depend on it.
One thing in particular is `git annex info` which lists the uuids and
descriptions; if the current repo has been initialized in some way that
means it does not have a description, it would not show up w/o that.

(Not only repos created due to this bug might lack that. For example a repo
that was marked dead and had --drop-dead delete its git-annex branch info,
and then came back from the dead would similarly not be in the uuid.log.
Also there have been other versions of git-annex that didn't set a default
description; for years there was no default description.)

Annex/Init.hs

@@ -92,7 +92,7 @@ initialize mdescription mversion = checkCanInitialize $ do
 	u <- getUUID
 	{- Avoid overwriting existing description with a default
 	 - description. -}
-	whenM (pure (isJust mdescription) <||> not . M.member u <$> uuidDescMap) $
+	whenM (pure (isJust mdescription) <||> not . M.member u <$> uuidDescMapRaw) $
 		describeUUID u =<< genDescription mdescription
 
 -- Everything except for uuid setup, shared clone setup, and initial

CHANGELOG

@@ -12,6 +12,8 @@ git-annex (7.20190616) UNRELEASED; urgency=medium
     fix a case where importfeed downloaded a partial feed from such a server.
   * importfeed: When there's a problem parsing the feed, --debug will
     output the feed content that was downloaded.
+  * init: Fix a reversion in the last release that prevented automatically
+    generating and setting a description for the repository.
 
  -- Joey Hess <id@joeyh.name>  Sat, 15 Jun 2019 12:38:25 -0400
 

Logs/UUID.hs

@@ -11,7 +11,8 @@ module Logs.UUID (
 	uuidLog,
 	describeUUID,
 	uuidDescMap,
-	uuidDescMapLoad
+	uuidDescMapLoad,
+	uuidDescMapRaw,
 ) where
 
 import Types.UUID
@@ -38,13 +39,13 @@ describeUUID uuid desc = do
 uuidDescMap :: Annex UUIDDescMap
 uuidDescMap = maybe uuidDescMapLoad return =<< Annex.getState Annex.uuiddescmap
 
-{- Read the uuidLog into a simple Map.
+{- Read the uuidLog into a map, and cache it for later use.
  -
- - The UUID of the current repository is included explicitly, since
+ - If the current repository has not been described, it is still included
- - it may not have been described and otherwise would not appear. -}
+ - in the map with an empty description. -}
 uuidDescMapLoad :: Annex UUIDDescMap
 uuidDescMapLoad = do
-	m <- simpleMap . parseUUIDLog <$> Annex.Branch.get uuidLog
+	m <- uuidDescMapRaw
 	u <- Annex.UUID.getUUID
 	let m' = M.insertWith preferold u mempty m
 	Annex.changeState $ \s -> s { Annex.uuiddescmap = Just m' }
@@ -52,5 +53,9 @@ uuidDescMapLoad = do
   where
 	preferold = flip const
 
+{- Read the uuidLog into a map. Includes only actually set descriptions. -}
+uuidDescMapRaw :: Annex UUIDDescMap
+uuidDescMapRaw = simpleMap . parseUUIDLog <$> Annex.Branch.get uuidLog
+
 parseUUIDLog :: L.ByteString -> Log UUIDDesc
 parseUUIDLog = parseLogOld (UUIDDesc <$> A.takeByteString)

doc/bugs/annex_init_no_longer_generates_default_description.mdwn

@@ -94,3 +94,5 @@ init  ok
 ```
 
 Note that the description for here is a blank string.
+
+> [[fixed|done]] --[[Joey]]

doc/bugs/annex_init_no_longer_generates_default_description/comment_3_6edae77c6ee7e4c4f94f9c0daff375ad._comment

@@ -0,0 +1,13 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 3"""
+ date="2019-06-21T00:12:51Z"
+ content="""
+Thanks Kyle, that does point at the problem. In uuidDescMapLoad
+it implicitly adds the UUID of the current repo, with an empty 
+description if none is set. So, the added check of uuidDescMap
+always finds the UUID in it already. Your uuidDescMapLoad hack
+avoids this by loading the map before the current repo has a UUID.
+
+Fixed more cleanly..
+"""]]