parsing: balance real and balanced virtual postings separately, allow an amount-less balanced virtual posting

hledger-lib/Ledger/Transaction.hs

@@ -126,19 +126,22 @@ isTransactionBalanced t = isReallyZeroMixedAmountCost rsum && isReallyZeroMixedA
 -- return an error message instead.
 balanceTransaction :: Transaction -> Either String Transaction
 balanceTransaction t@Transaction{tpostings=ps}
-    | length missingamounts' > 1 = Left $ printerr "could not balance this transaction (too many missing amounts)"
+    | length rwithoutamounts > 1 || length bvwithoutamounts > 1
+        = Left $ printerr "could not balance this transaction (too many missing amounts)"
     | not $ isTransactionBalanced t' = Left $ printerr $ nonzerobalanceerror t'
     | otherwise = Right t'
     where
-      (withamounts, missingamounts) = partition hasAmount $ filter isReal ps
-      (_, missingamounts') = partition hasAmount ps
-      t' = t{tpostings=ps'}
-      ps' | length missingamounts == 1 = map balance ps
-          | otherwise = ps
+      rps = filter isReal ps
+      bvps = filter isBalancedVirtual ps
+      (rwithamounts, rwithoutamounts) = partition hasAmount rps
+      (bvwithamounts, bvwithoutamounts) = partition hasAmount bvps
+      t' = t{tpostings=map balance ps}
           where 
-            balance p | isReal p && not (hasAmount p) = p{pamount = costOfMixedAmount (-otherstotal)}
+            balance p | not (hasAmount p) && isReal p
+                          = p{pamount = costOfMixedAmount (-(sum $ map pamount rwithamounts))}
+                      | not (hasAmount p) && isBalancedVirtual p
+                          = p{pamount = costOfMixedAmount (-(sum $ map pamount bvwithamounts))}
                       | otherwise = p
-                      where otherstotal = sum $ map pamount withamounts
       printerr s = intercalate "\n" [s, showTransactionUnelided t]
 
 nonzerobalanceerror :: Transaction -> String

tests/amountless-virtual-postings.test

@@ -1,9 +0,0 @@
-# again, complain like ledger, but we could handle this
-./hledger -f - print
-<<<
-2009/1/1 x
- a  1
- b
- (c)
- (d)
->>>2 /too many missing/

tests/missing-real-and-virtual-amt.test

@@ -1,9 +0,0 @@
-# could balance this, but complain instead like ledger
-./hledger -f - register
-<<<
-2009/6/24 carwash
-    equity:draw:personal:transportation:car:carwash     $3.50
-    assets:cash
-    [expenses:car]                                      $3.50
-    [simon]
->>>2 /too many missing/

tests/virtual.test

@@ -5,24 +5,44 @@
   (virtual)  100
   a  1
   b
+#
 # 2. balanced virtual postings should be required to balance (themselves)
 ./hledger -f-
 <<<
 2010/1/1 x
-  [balanced virtual]  100
+  [balanced virtual]  10
   a  1
   b
 >>>= !0
+#
+# 3. balanced virtual postings should be required to balance (themselves)
 ./hledger -f-
 <<<
 2010/1/1 x
-  [balanced virtual]  100
-  [balanced virtual]  -100
+  [balanced virtual]  10
+  [balanced virtual]  -10
   a  1
   b
-# 3. a virtual posting with implicit amount should be handled correctly
+#
+# 4. a virtual posting with implicit amount should be handled correctly
 ./hledger -f-
 <<<
 2010/1/1 x
-    [a]    1
-    [b]
+  [a]    10
+  [b]
+#
+# 5. real and balanced virtual postings are balanced separately, and multiple blank virtuals are ok
+./hledger -f-
+<<<
+2010/1/1 x
+  a  1
+  b
+  [e]  10
+  [f]
+  (c)
+  (d)
+>>>
+                   1  a
+                  -1  b
+                  10  e
+                 -10  f