print: always show zero amounts as 0, hiding any commodity/decimal places/price, like ledger

hledger-lib/Ledger/Transaction.hs

@@ -82,7 +82,7 @@ showTransaction' elide effective t =
             showpostingnoamt p = rstrip $ showacct p ++ "              " ++ showcomment (pcomment p)
             showacct p = "    " ++ showstatus p ++ printf (printf "%%-%ds" w) (showAccountName Nothing (ptype p) (paccount p))
             w = maximum $ map (length . paccount) ps
-            showamount = printf "%12s" . showMixedAmount
+            showamount = printf "%12s" . showMixedAmountOrZero
             showcomment s = if null s then "" else "  ; "++s
             showstatus p = if pstatus p then "* " else ""
 

tests/zero-handling.test

@@ -0,0 +1,12 @@
+# a zero amount is always displayed as just "0", regardless of any commodity/decimal places/price (like ledger)
+#
+-f- print --empty
+<<<
+2010/3/1 x
+  a  $0.00 @ 3EUR
+  b
+>>>
+2010/03/01 x
+    a             0
+    b             0
+