more partial function removal

Left a few Prelude.head's in where it was checked not null and too hard to
remove, etc.

Logs/Location.hs

@@ -68,7 +68,7 @@ logFile key = hashDirLower key ++ keyFile key ++ ".log"
 {- Converts a log filename into a key. -}
 logFileKey :: FilePath -> Maybe Key
 logFileKey file
-	| end == ".log" = fileKey beginning
+	| ext == ".log" = fileKey base
 	| otherwise = Nothing
 	where
-		(beginning, end) = splitAt (length file - 4) file
+		(base, ext) = splitAt (length file - 4) file

Logs/Remote.hs

@@ -73,14 +73,13 @@ configUnEscape = unescape
 			| c == '&' = entity rest
 			| otherwise = c : unescape rest
 		entity s = if ok
-				then chr (read num) : unescape rest
+				then chr (Prelude.read num) : unescape rest
 				else '&' : unescape s
 			where
 				num = takeWhile isNumber s
 				r = drop (length num) s
 				rest = drop 1 r
-				ok = not (null num) && 
-					not (null r) && head r == ';'
+				ok = not (null num) && take 1 r == ";"
 
 {- for quickcheck -}
 prop_idempotent_configEscape :: String -> Bool

Logs/Trust.hs

@@ -54,18 +54,16 @@ trustMap = do
 		Just m -> return m
 		Nothing -> do
 			overrides <- M.fromList <$> Annex.getState Annex.forcetrust
-			m <- (M.union overrides . simpleMap . parseLog parseTrust) <$>
+			m <- (M.union overrides . simpleMap . parseLog (Just . parseTrust)) <$>
 				Annex.Branch.get trustLog
 			Annex.changeState $ \s -> s { Annex.trustmap = Just m }
 			return m
 
-parseTrust :: String -> Maybe TrustLevel
-parseTrust s
-	| length w > 0 = Just $ parse $ head w
-	-- back-compat; the trust.log used to only list trusted repos
-	| otherwise = Just Trusted
+{- The trust.log used to only list trusted repos, without a field for the
+ - trust status, which is why this defaults to Trusted. -}
+parseTrust :: String -> TrustLevel
+parseTrust s = maybe Trusted parse $ headMaybe $ words s
 	where
-		w = words s
 		parse "1" = Trusted
 		parse "0" = UnTrusted
 		parse "X" = DeadTrusted
@@ -82,6 +80,6 @@ trustSet :: UUID -> TrustLevel -> Annex ()
 trustSet uuid@(UUID _) level = do
 	ts <- liftIO getPOSIXTime
 	Annex.Branch.change trustLog $
-		showLog showTrust . changeLog ts uuid level . parseLog parseTrust
+		showLog showTrust . changeLog ts uuid level . parseLog (Just . parseTrust)
 	Annex.changeState $ \s -> s { Annex.trustmap = Nothing }
 trustSet NoUUID _ = error "unknown UUID; cannot modify trust level"

Logs/UUID.hs

@@ -57,9 +57,9 @@ fixBadUUID = M.fromList . map fixup . M.toList
 				kuuid = fromUUID k
 				isbad = not (isuuid kuuid) && isuuid lastword
 				ws = words $ value v
-				lastword = last ws
+				lastword = Prelude.last ws
 				fixeduuid = toUUID lastword
-				fixedvalue = unwords $ kuuid: init ws
+				fixedvalue = unwords $ kuuid: Prelude.init ws
 		-- For the fixed line to take precidence, it should be
 		-- slightly newer, but only slightly.
 		newertime (LogEntry (Date d) _) = d + minimumPOSIXTimeSlice