From 7102d6f9e8f75380de4bff079cce0f9c336cfe74 Mon Sep 17 00:00:00 2001
From: Simon Michael <simon@joyful.com>
Date: Wed, 14 Sep 2022 16:56:28 -1000
Subject: [PATCH] fix: balcmds: handle an empty totals column in html output
 (#1933)

---
 hledger/Hledger/Cli/Commands/Balance.hs | 46 +++++++++++++++++--------
 hledger/test/balance/balance.test       |  5 +++
 2 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/hledger/Hledger/Cli/Commands/Balance.hs b/hledger/Hledger/Cli/Commands/Balance.hs
index 0ae3ce4d6..7fb25c142 100644
--- a/hledger/Hledger/Cli/Commands/Balance.hs
+++ b/hledger/Hledger/Cli/Commands/Balance.hs
@@ -573,14 +573,20 @@ multiBalanceReportHtmlRows ropts mbr =
 -- | Render one MultiBalanceReport heading row as a HTML table row.
 multiBalanceReportHtmlHeadRow :: ReportOpts -> [T.Text] -> Html ()
 multiBalanceReportHtmlHeadRow _ [] = mempty  -- shouldn't happen
-multiBalanceReportHtmlHeadRow ropts (acct:rest) =
+multiBalanceReportHtmlHeadRow ropts (acct:cells) =
   let
     defstyle = style_ ""
     (amts,tot,avg)
-      | row_total_ ropts && average_ ropts = (init $ init rest, [last $ init rest], [last rest])
-      | row_total_ ropts                   = (init rest,        [last rest],        [])
-      |                     average_ ropts = (init rest,        [],                 [last rest])
-      | otherwise                          = (rest,             [],                 [])
+      | row_total_ ropts && average_ ropts = (ini2, sndlst2, lst2)
+      | row_total_ ropts                   = (ini1, lst1,    [])
+      |                     average_ ropts = (ini1, [],      lst1)
+      | otherwise                          = (amts, [],      [])
+      where
+        n = length cells
+        (ini1,lst1)    = splitAt (n-1) cells
+        (ini2, rest)   = splitAt (n-2) cells
+        (sndlst2,lst2) = splitAt 1 rest
+
   in
     tr_ $ mconcat $
           td_ [class_ "account"]              (toHtml acct)
@@ -591,14 +597,19 @@ multiBalanceReportHtmlHeadRow ropts (acct:rest) =
 -- | Render one MultiBalanceReport data row as a HTML table row.
 multiBalanceReportHtmlBodyRow :: ReportOpts -> [T.Text] -> Html ()
 multiBalanceReportHtmlBodyRow _ [] = mempty  -- shouldn't happen
-multiBalanceReportHtmlBodyRow ropts (label:rest) =
+multiBalanceReportHtmlBodyRow ropts (label:cells) =
   let
     defstyle = style_ "text-align:right"
     (amts,tot,avg)
-      | row_total_ ropts && average_ ropts = (init $ init rest, [last $ init rest], [last rest])
-      | row_total_ ropts                   = (init rest,        [last rest],        [])
-      |                     average_ ropts = (init rest,        [],                 [last rest])
-      | otherwise                          = (rest,             [],                 [])
+      | row_total_ ropts && average_ ropts = (ini2, sndlst2, lst2)
+      | row_total_ ropts                   = (ini1, lst1,    [])
+      |                     average_ ropts = (ini1, [],      lst1)
+      | otherwise                          = (amts, [],      [])
+      where
+        n = length cells
+        (ini1,lst1)    = splitAt (n-1) cells
+        (ini2, rest)   = splitAt (n-2) cells
+        (sndlst2,lst2) = splitAt 1 rest
   in
     tr_ $ mconcat $
           td_ [class_ "account", style_ "text-align:left"]  (toHtml label)
@@ -615,14 +626,19 @@ multiBalanceReportHtmlFootRow _ropts [] = mempty
 --   : repeat nullmixedamt zeros
 --  ++ (if row_total_ ropts then [nullmixedamt] else [])
 --  ++ (if average_ ropts   then [nullmixedamt]   else [])
-multiBalanceReportHtmlFootRow ropts (acct:rest) =
+multiBalanceReportHtmlFootRow ropts (acct:cells) =
   let
     defstyle = style_ "text-align:right"
     (amts,tot,avg)
-      | row_total_ ropts && average_ ropts = (init $ init rest, [last $ init rest], [last rest])
-      | row_total_ ropts                   = (init rest,        [last rest],        [])
-      |                     average_ ropts = (init rest,        [],                 [last rest])
-      | otherwise                          = (rest,             [],                 [])
+      | row_total_ ropts && average_ ropts = (ini2, sndlst2, lst2)
+      | row_total_ ropts                   = (ini1, lst1,    [])
+      |                     average_ ropts = (ini1, [],      lst1)
+      | otherwise                          = (amts, [],      [])
+      where
+        n = length cells
+        (ini1,lst1)    = splitAt (n-1) cells
+        (ini2, rest)   = splitAt (n-2) cells
+        (sndlst2,lst2) = splitAt 1 rest
   in
     tr_ $ mconcat $
           th_ [style_ "text-align:left"]             (toHtml acct)
diff --git a/hledger/test/balance/balance.test b/hledger/test/balance/balance.test
index 8875392bd..e3828f1b4 100644
--- a/hledger/test/balance/balance.test
+++ b/hledger/test/balance/balance.test
@@ -194,3 +194,8 @@ account a:ac:aca
 account b
 $ hledger -f - balance -NE --declared not:a
                    0  b
+
+# 13. An empty totals column does not break HTML output (#1933).
+<
+$ hledger -f- bal -YT -O html
+> //