journal: really don't parse + before an amount as part of the commodity (fixes #181 harder)

hledger-lib/Hledger/Data/Commodity.hs

@@ -17,8 +17,8 @@ import Hledger.Data.Types
 import Hledger.Utils
 
 
--- characters than can't be in a non-quoted commodity symbol
-nonsimplecommoditychars = "0123456789-.@;\n \"{}=" :: String
+-- characters that may not be used in a non-quoted commodity symbol
+nonsimplecommoditychars = "0123456789-+.@;\n \"{}=" :: String
 
 quoteCommoditySymbolIfNeeded s | any (`elem` nonsimplecommoditychars) s = "\"" ++ s ++ "\""
                                | otherwise = s

hledger-lib/Hledger/Read/JournalReader.hs

@@ -658,12 +658,12 @@ signp = do
 leftsymbolamount :: GenParser Char JournalContext Amount
 leftsymbolamount = do
   sign <- signp
-  let applysign = if sign=="-" then negate else id
   c <- commoditysymbol 
   sp <- many spacenonewline
   (q,prec,dec,sep,seppos) <- numberp
   let s = amountstyle{ascommodityside=L, ascommodityspaced=not $ null sp, asdecimalpoint=dec, asprecision=prec, asseparator=sep, asseparatorpositions=seppos}
   p <- priceamount
+  let applysign = if sign=="-" then negate else id
   return $ applysign $ Amount c q p s
   <?> "left-symbol amount"