From 70bc472ffe93b80ad12db56e75332d09d3b0c1df Mon Sep 17 00:00:00 2001
From: John Ralls <jralls@ceridwen.us>
Date: Thu, 20 Sep 2018 17:25:44 -0700
Subject: [PATCH] Revert "[net-charts] deoptimize accounts-list"

This reverts commit 941acee04e3598c18eda8cb68c3b024da6f73ab1. It did
indeed deoptimize creating a list of split-balances for time reports.
---
 .../report/standard-reports/net-charts.scm    | 56 +++++++++++++++----
 1 file changed, 46 insertions(+), 10 deletions(-)

diff --git a/gnucash/report/standard-reports/net-charts.scm b/gnucash/report/standard-reports/net-charts.scm
index 5a633e3fde..9e1e885a02 100644
--- a/gnucash/report/standard-reports/net-charts.scm
+++ b/gnucash/report/standard-reports/net-charts.scm
@@ -33,6 +33,8 @@
 (use-modules (gnucash gnc-module))
 (use-modules (gnucash gettext))
 
+(use-modules (gnucash report report-system report-collectors))
+(use-modules (gnucash report report-system collectors))
 (use-modules (gnucash report standard-reports category-barchart)) ; for guids of called reports
 (gnc:module-load "gnucash/report/report-system" 0)
 
@@ -304,16 +306,50 @@
 
     (if
      (not (null? accounts))
-     (let* ((assets-list (process-datelist
-                          (if inc-exp?
-                              accounts
-                              (assoc-ref classified-accounts ACCT-TYPE-ASSET))
-                          dates-list #t))
-            (liability-list (process-datelist
-                             (if inc-exp?
-                                 accounts
-                                 (assoc-ref classified-accounts ACCT-TYPE-LIABILITY))
-                             dates-list #f))
+     (let* ((the-account-destination-alist
+             (if inc-exp?
+                 (append (map (lambda (account) (cons account 'asset))
+                              (assoc-ref classified-accounts ACCT-TYPE-INCOME))
+                         (map (lambda (account) (cons account 'liability))
+                              (assoc-ref classified-accounts ACCT-TYPE-EXPENSE)))
+                 (append  (map (lambda (account) (cons account 'asset))
+                               (assoc-ref classified-accounts ACCT-TYPE-ASSET))
+                          (map (lambda (account) (cons account 'liability))
+                               (assoc-ref classified-accounts ACCT-TYPE-LIABILITY)))))
+            (account-reformat (if inc-exp?
+                                  (lambda (account result)
+                                    (map (lambda (collector date-interval)
+                                           (gnc:monetary-neg (collector->monetary collector (second date-interval))))
+                                         result dates-list))
+                                  (lambda (account result)
+                                    (let ((commodity-collector (gnc:make-commodity-collector)))
+                                      (collector-end (fold (lambda (next date list-collector)
+                                                             (commodity-collector 'merge next #f)
+                                                             (collector-add list-collector
+                                                                            (collector->monetary
+                                                                             commodity-collector date)))
+                                                           (collector-into-list)
+                                                           result
+                                                           dates-list))))))
+            (work (category-by-account-report-work inc-exp?
+                                                   dates-list
+                                                   the-account-destination-alist
+                                                   (lambda (account date)
+                                                     (make-gnc-collector-collector))
+                                                   account-reformat))
+            (rpt (category-by-account-report-do-work work (cons 50 90)))
+            (assets (assoc-ref rpt 'asset))
+            (liabilities (assoc-ref rpt 'liability))
+            (assets-list (if assets
+                             (car assets)
+                             (map (lambda (d)
+                                    (gnc:make-gnc-monetary report-currency 0))
+                                  dates-list)))
+            (liability-list (if liabilities
+                                (car liabilities)
+                                (map (lambda (d)
+                                       (gnc:make-gnc-monetary report-currency 0))
+                                     dates-list)))
             (net-list (map monetary+ assets-list liability-list))
             ;; Here the date strings for the x-axis labels are
             ;; created.