[FIX] account: reconciliation widget: Don't loose pager on adding last line

Have a statement line with multiple pages of propositions
Go to the last page
Add everything

Before this commit, after clicking on the last item of the list,
a write-off creation was displayed, without any means to come back to the other
propositions

After this commit, we display the page before

addons/account/static/src/js/reconciliation/reconciliation_model.js

@@ -128,6 +128,20 @@ var StatementModel = BasicModel.extend({
         var line = this.getLine(handle);
         var prop = _.clone(_.find(line.mv_lines, {'id': mv_line_id}));
         this._addProposition(line, prop);
+
+        // Check whether we have some propositions left
+        // If we don't, it means we are on an empty page
+        // so let's go back to the previous page
+        // Through the offset
+        var propLineIds = _.map(line.reconciliation_proposition, function(prop) {
+                return prop.id;
+            });
+        var leftOversProps = _.filter(line.mv_lines, function(mv_line) {
+            return propLineIds.indexOf(mv_line.id) === -1;
+        });
+        if (line.offset && !leftOversProps.length) {
+            line.offset -= line.limitMoveLines;
+        }
         return $.when(this._computeLine(line), this._performMoveLine(handle));
     },
     /**

addons/account/static/tests/reconciliation_tests.js

@@ -1798,5 +1798,54 @@ QUnit.module('account', {
 
         clientAction.destroy();
     });
+
+    QUnit.test('Automatic Reconciliation: Don\'t loose pager when adding last line of a page', function (assert) {
+        assert.expect(2);
+
+        function standard_partner (list, partner_id) {
+            _.each(list, function (item) {
+                item.partner_id = partner_id;
+            });
+        };
+
+        this.params.options.params.limitMoveLines = 1;
+        standard_partner(this.params.mv_lines['[5,"",0,6]'], 8);
+
+        // Overlap of those requests is normal
+        // the pager is implemented as:
+        // if there is at least 1 more line than my limit, the pager is active
+        this.params.mv_lines['[5,"",0,2]'] = this.params.mv_lines['[5,"",0,6]'].slice(0,2);
+        this.params.mv_lines['[5,"",1,2]'] = this.params.mv_lines['[5,"",0,6]'].slice(1,2);
+
+        var clientAction = new ReconciliationClientAction.StatementAction(null, this.params.options);
+        testUtils.addMockEnvironment(clientAction, {
+            data: this.params.data,
+            session: {
+                currencies: {
+                    3: {
+                        digits: [69, 2],
+                        position: "before",
+                        symbol: "$"
+                    }
+                }
+            },
+        });
+        clientAction.appendTo($('#qunit-fixture'));
+
+        var widget = clientAction.widgets[0];
+
+        var $nextPage = widget.$('.match .match_controls .fa-chevron-right:not(disabled)');
+        assert.ok($nextPage.length,
+            'We should have a next page');
+        $nextPage.click();
+
+        // Add the second's page record
+        widget.$('.match tr[data-line-id=112] td:first').click();
+
+        assert.ok(widget.$('.match tr[data-line-id=109]').length,
+            'the record of the first page must be proposed');
+
+        clientAction.destroy();
+    });
 });
 });