Bug 330930 - Financial Calculator resets payment period to zero

When the preference option 'Numbers, Date, Time' ->
'Automatic Decimal Point' is set and you change the 'Payment periods'
to say 11 you end up with zero as number entered becomes 0.11

To fix this treat the Periods GNCAmountEdit widget as a plain GtkEntry
and not use the GNCAmountEdit evaluate functions.

gnucash/gnome/dialog-fincalc.c

@@ -183,12 +183,21 @@ gui_to_fi(FinCalcDialog *fcd)
     GtkToggleButton *toggle;
     gnc_numeric npp;
     int i;
+    const gchar *text;
 
     if (fcd == NULL)
         return;
 
-    npp =
-        gnc_amount_edit_get_amount(GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]));
+    /* treat PAYMENT_PERIODS as a plain GtkEntry */
+    text = gtk_entry_get_text (GTK_ENTRY(GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS])));
+    if (text && *text)
+    {
+        gnc_numeric out;
+        gboolean result = string_to_gnc_numeric (text, &out);
+        npp = gnc_numeric_convert (out, 1, GNC_HOW_RND_TRUNC);
+    }
+    else
+        npp = gnc_numeric_zero ();
     fcd->financial_info.npp = npp.num;
 
     fcd->financial_info.ir =
@@ -338,10 +347,14 @@ can_calc_value(FinCalcDialog *fcd, FinCalcValue value, int *error_item)
                 return missing;
             }
 
-            if (!gnc_amount_edit_evaluate (GNC_AMOUNT_EDIT (fcd->amounts[i])))
+            /* treat PAYMENT_PERIODS as a plain GtkEntry */
+            if (i != PAYMENT_PERIODS)
             {
-                *error_item = i;
-                return bad_exp;
+                if (!gnc_amount_edit_evaluate (GNC_AMOUNT_EDIT (fcd->amounts[i])))
+                {
+                    *error_item = i;
+                    return bad_exp;
+                }
             }
         }
 
@@ -371,17 +384,27 @@ can_calc_value(FinCalcDialog *fcd, FinCalcValue value, int *error_item)
     case PRESENT_VALUE:
     case PERIODIC_PAYMENT:
     case FUTURE_VALUE:
-        nvalue = gnc_amount_edit_get_amount
-                 (GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]));
-        if (gnc_numeric_zero_p (nvalue))
-        {
-            *error_item = PAYMENT_PERIODS;
-            return _("The number of payments cannot be zero.");
-        }
-        if (gnc_numeric_negative_p (nvalue))
         {
-            *error_item = PAYMENT_PERIODS;
-            return _("The number of payments cannot be negative.");
+            /* treat PAYMENT_PERIODS as a plain GtkEntry */
+            GNCAmountEdit *edit = GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]);
+            const gchar *text = gtk_entry_get_text (GTK_ENTRY(edit));
+            gboolean result = string_to_gnc_numeric (text, &nvalue);
+
+            if (!result)
+            {
+                *error_item = PAYMENT_PERIODS;
+                return bad_exp;
+            }
+            if (gnc_numeric_zero_p (nvalue))
+            {
+                *error_item = PAYMENT_PERIODS;
+                return _("The number of payments cannot be zero.");
+            }
+            if (gnc_numeric_negative_p (nvalue))
+            {
+                *error_item = PAYMENT_PERIODS;
+                return _("The number of payments cannot be negative.");
+            }
         }
         break;
     default: