lib: make --auto work on --forecast transactions

hledger/Hledger/Cli/Utils.hs

@@ -164,13 +164,16 @@ journalAddForecast opts@CliOpts{reportopts_=ropts} j = do
   let forecastend = dbg2 "forecastend" $ fromMaybe (addDays 180 today) mspecifiedend
 
   let forecastspan = DateSpan (Just forecaststart) (Just forecastend)
-      forecasttxns = [ txnTieKnot t | pt <- jperiodictxns j
-                                    , t <- runPeriodicTransaction pt forecastspan
-                                    , spanContainsDate forecastspan (tdate t)
-                                    ]
+      forecasttxns =
+        -- If there are forecast transaction, lets apply transaction modifiers to them
+        map (foldr (flip (.) . transactionModifierToFunction) id (jtxnmodifiers j)) $
+        [ txnTieKnot t | pt <- jperiodictxns j
+                       , t <- runPeriodicTransaction pt forecastspan
+                       , spanContainsDate forecastspan (tdate t)
+                       ]
   return $
     if forecast_ ropts 
-      then journalBalanceTransactions' opts j{ jtxns = forecasttxns ++ jtxns j }  -- XXX wouldn't appending be better ?
+      then journalBalanceTransactions' opts j{ jtxns = concat [forecasttxns, jtxns j] }
       else j
   where      
     journalBalanceTransactions' opts j =

tests/print/auto.test

@@ -164,3 +164,31 @@ because it is also included in transaction modifiers.
 
 >=1
 
+## Transaction modifiers affect forecast transactions
+<
+= ^income
+  (liabilities:tax)  *.33  ; income tax
+
+~ monthly from 2016-01   paycheck
+    income:remuneration     $-100
+    income:donations         $-15
+    assets:bank
+
+2016/1/3 withdraw
+    assets:cash             $20
+    assets:bank
+
+$ hledger print -f- --auto --forecast -b 2016-01 -e 2016-03
+2016/01/03 withdraw
+    assets:cash             $20
+    assets:bank
+
+2016/02/01 paycheck
+    ; recur: monthly from 2016-01
+    income:remuneration           $-100
+    (liabilities:tax)              $-33    ; income tax
+    income:donations               $-15
+    (liabilities:tax)               $-5    ; income tax
+    assets:bank
+
+>=