From aa332a4ed2b262ae7f8d74bed2d5cc8dc5a375f7 Mon Sep 17 00:00:00 2001
From: David Rosca <nowrep@gmail.com>
Date: Sun, 4 Feb 2018 15:51:12 +0100
Subject: [PATCH] VerticalTabs: Reject drop on last row in pinned tabs model

It seems like a weird behavior in Qt because source model receives
drop on last index (in filter model) as drop on last index in source
model instead of filter model and it can't make a right decision.

Source model:
| 1 | 2 | 3 | 4 | 5 | 6 |
Filter model:
| 1 | 2 | 3 | 4 |
                ^
Dropping here propagates to source model as drop on index 7, not 5.

Let's just ignore this case to workaround it.
---
 src/plugins/VerticalTabs/tabfiltermodel.cpp     | 12 ++++++++++++
 src/plugins/VerticalTabs/tabfiltermodel.h       |  4 ++++
 src/plugins/VerticalTabs/verticaltabswidget.cpp |  1 +
 3 files changed, 17 insertions(+)

diff --git a/src/plugins/VerticalTabs/tabfiltermodel.cpp b/src/plugins/VerticalTabs/tabfiltermodel.cpp
index f2af6e24f..b411747d6 100644
--- a/src/plugins/VerticalTabs/tabfiltermodel.cpp
+++ b/src/plugins/VerticalTabs/tabfiltermodel.cpp
@@ -37,6 +37,11 @@ void TabFilterModel::setFilterPinnedTabs(bool filter)
     invalidateFilter();
 }
 
+void TabFilterModel::setRejectDropOnLastIndex(bool reject)
+{
+    m_rejectDropOnLastIndex = reject;
+}
+
 bool TabFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const
 {
     if (m_mode == NoFilter) {
@@ -47,3 +52,10 @@ bool TabFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourcePa
     return index.data(TabModel::PinnedRole).toBool() != m_filterPinnedTabs;
 }
 
+bool TabFilterModel::canDropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const
+{
+    if (m_rejectDropOnLastIndex && row == rowCount()) {
+        return false;
+    }
+    return QSortFilterProxyModel::canDropMimeData(data, action, row, column, parent);
+}
diff --git a/src/plugins/VerticalTabs/tabfiltermodel.h b/src/plugins/VerticalTabs/tabfiltermodel.h
index aa44cf20c..cb6676cbc 100644
--- a/src/plugins/VerticalTabs/tabfiltermodel.h
+++ b/src/plugins/VerticalTabs/tabfiltermodel.h
@@ -30,8 +30,11 @@ public:
 
     void setFilterPinnedTabs(bool pinned);
 
+    void setRejectDropOnLastIndex(bool reject);
+
 private:
     bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const;
+    bool canDropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const override;
 
     enum Mode {
         NoFilter,
@@ -40,4 +43,5 @@ private:
 
     Mode m_mode = NoFilter;
     bool m_filterPinnedTabs = false;
+    bool m_rejectDropOnLastIndex = false;
 };
diff --git a/src/plugins/VerticalTabs/verticaltabswidget.cpp b/src/plugins/VerticalTabs/verticaltabswidget.cpp
index 0938d45e1..2caed14b1 100644
--- a/src/plugins/VerticalTabs/verticaltabswidget.cpp
+++ b/src/plugins/VerticalTabs/verticaltabswidget.cpp
@@ -43,6 +43,7 @@ VerticalTabsWidget::VerticalTabsWidget(BrowserWindow *window)
     m_pinnedView = new TabListView(this);
     TabFilterModel *model = new TabFilterModel(m_pinnedView);
     model->setFilterPinnedTabs(false);
+    model->setRejectDropOnLastIndex(true);
     model->setSourceModel(m_window->tabModel());
     m_pinnedView->setModel(model);
     m_pinnedView->setHideWhenEmpty(true);