bs/is: fix "Ratio has zero denominator" error (take 2) (#535)

hledger/Hledger/Cli/Balance.hs

@@ -531,8 +531,8 @@ balanceReportAsTable opts (MultiBalanceReport (colspans, items, (coltotals,tot,a
     addtotalrow | no_total_ opts = id
                 | otherwise      = (+----+ (row "" $
                                     coltotals
-                                    ++ (if row_total_ opts then [tot] else [])
+                                    ++ (if row_total_ opts && not (null coltotals) then [tot] else [])
-                                    ++ (if average_ opts   then [avg] else [])
+                                    ++ (if average_ opts && not (null coltotals)   then [avg] else [])
                                     ))
 
 -- | Figure out the overall date span of a multicolumn balance report.

hledger/Hledger/Cli/BalanceView.hs

@@ -148,8 +148,8 @@ balanceviewReport BalanceView{..} CliOpts{command_=cmd, reportopts_=ropts, rawop
                   mergedTabl
                   +====+
                   row "Total"
-                      (sumAmts ++ (if row_total_ ropts' then [totsum] else [])
+                      (sumAmts ++ (if row_total_ ropts' && not (null sumAmts) then [totsum] else [])
-                               ++ (if average_ ropts'   then [totavg] else [])
+                               ++ (if average_ ropts' && not (null sumAmts)   then [totavg] else [])
                       )
         putStrLn title
         putStrLn $ renderBalanceReportTable ropts totTabl