- Fix bugs in finding potential duplicate transactions to merge.

- Fix bug in keeping correct selection after merging duplicates.

Source/WPF/MyMoney/Database/Money.cs

@@ -8524,9 +8524,8 @@ public static bool IsRecurring(Transaction t, Transaction u, IList<Transaction>
             // same (or similar) TimeSpan then this might be a recurring transaction.
             TimeSpan span = t.Date - u.Date;
             decimal days = (decimal)Math.Abs(span.TotalDays);
-            if (days == 0 || t.Amount == 0)
+            if (days == 0)
             {
-                // unlikely to have a recurring payment on the same day or for zero dollars!
                 return false;
             }
 
@@ -8540,7 +8539,8 @@ public static bool IsRecurring(Transaction t, Transaction u, IList<Transaction>
                 i = j;
             }
 
-            List<double> daysBetween = new List<double>();
+            // create a new list so we can sort by date, since 'tc' is not necessarily yet.
+            List<Transaction> similarTransactions = new List<Transaction>();
             for (--i; i > 0; i--)
             {
                 Transaction w = tc[i];
@@ -8553,19 +8553,34 @@ public static bool IsRecurring(Transaction t, Transaction u, IList<Transaction>
                 // then it is probably a recurring instance.
                 if (w.PayeeName == t.PayeeName && Math.Abs((w.Amount - t.Amount) * 100 / t.Amount) < amountDeltaPercent)
                 {
-                    TimeSpan diff = start.Date - w.Date;
+                    similarTransactions.Add(w);
+                    if (similarTransactions.Count > 10)
+                    {
+                        break; // should be enough.
+                    }
+                }
+            }
+
+            if (similarTransactions.Count < recurringCount)
+            {
+                return false;
+            }
+
+            similarTransactions.Sort((x, y) => { return x.Date.CompareTo(y.Date); });
+
+            List<double> daysBetween = new List<double>();
+            Transaction previous = null;
+            foreach (Transaction s in similarTransactions) {
+                if (previous != null)
+                {
+                    TimeSpan diff = s.Date - previous.Date;
                     double diffDays = Math.Abs(diff.TotalDays);
                     if (diffDays > 0)
-                    {  // weed out duplicate payments.
+                    {  
                         daysBetween.Add(diffDays);
-                        if (daysBetween.Count > 10)
-                        {
-                            // that should be enough to see the pattern.
-                            break; 
-                        }
-                        start.Date = w.Date;
                     }
                 }
+                previous = s;
             }
 
             var filtered = MathHelpers.RemoveOutliers(daysBetween, 1);
@@ -8591,7 +8606,6 @@ private static bool IsPotentialDuplicate(Transaction t, Transaction u, int dayRa
                 // and if they are investment transactions the stock type and unit quanities have to be the same
                 IsPotentialDuplicate(t.Investment, u.Investment) &&
                 // if they both have unique FITID fields, then the bank is telling us these are not duplicates.
-                (string.IsNullOrEmpty(t.FITID) || string.IsNullOrEmpty(u.FITID) || t.FITID == u.FITID) &&
                 // they can't be both reconciled, because then we can't merge them!
                 (u.Status != TransactionStatus.Reconciled || t.Status != TransactionStatus.Reconciled) &&
                 // within specified date range

Source/WPF/MyMoney/Setup/changes.xml

@@ -3,6 +3,8 @@
   <change version="2.0.0.4" date="3/23/2022">
     - Add a way to link downloaded .pdf bank statements with your reconciled accounts during balancing
     - Add "Goto Statement" on transactions that automatically find and open any linked .pdf statement.    
+    - Fix bugs in finding potential duplicate transactions to merge.
+    - Fix bug in keeping correct selection after merging duplicates.
   </change>
   <change version="2.0.0.3" date="3/23/2022">
     - A few minor dark theme fixes, the save popup link color and message box icons.

Source/WPF/MyMoney/View Selectors/AccountsControl.xaml.cs

@@ -136,7 +136,7 @@ public AccountViewModel Selected
         #endregion
 
         #region EVENTS
-
+        private bool hideEvents;
         public event EventHandler SelectionChanged;
         public event EventHandler<ChangeEventArgs> BalanceAccount;
         public event EventHandler<ChangeEventArgs> SyncAccount;
@@ -342,6 +342,7 @@ void Rebind()
         {
             UpdateContextMenuView();
 
+            this.hideEvents = true;
             if (myMoney != null)
             {
                 //---------------------------------------------------------
@@ -396,6 +397,7 @@ void Rebind()
             {
                 this.items.Clear();
             }
+            this.hideEvents = false;
         }
 
 
@@ -479,7 +481,13 @@ void RaiseSelectionEvent(AccountViewModel selected, bool force)
             if ((force || this.selected != selected) && SelectionChanged != null)
             {
                 SetSelected(selected);
-                SelectionChanged(this, EventArgs.Empty);
+
+                // checked it really is a different account (could be different object
+                // but the same account because of a rebind).
+                if (!hideEvents)
+                {
+                    SelectionChanged(this, EventArgs.Empty);
+                }
             }
         }
 
@@ -878,6 +886,15 @@ public AccountItemViewModel(Account a)
             this.account.PropertyChanged -= OnPropertyChanged;
         }
 
+        public override bool Equals(object obj)
+        {
+            if (obj is AccountItemViewModel m)
+            {
+                return m.account == this.account;
+            }
+            return false;
+        }
+
         protected override void OnSelectedChanged() 
         {
             OnPropertyChanged("NameForeground");
@@ -1080,6 +1097,16 @@ public string Name
 
         public string Title { get; set; }
 
+        public override bool Equals(object obj)
+        {
+            if (obj is AccountSectionHeader m)
+            {
+                return m.Title == this.Title;
+            }
+            return false;
+        }
+
+
         public decimal BalanceInNormalizedCurrencyValue {
             get => balanceNormalized;
             set {