Avoid creating a new partition with a used mountpoint.

We get the mountpoints already used by other partitions, and
disable the Ok button in the "Create new partition" dialog if
the user selects/writes a mountpoint which is already used.

We are going to do the same in the Edit partition dialog
after testing.

src/modules/partition/gui/CreatePartitionDialog.cpp

@@ -40,8 +40,9 @@
 // Qt
 #include <QComboBox>
 #include <QDir>
-#include <QSet>
 #include <QListWidgetItem>
+#include <QPushButton>
+#include <QSet>
 
 static QSet< FileSystem::Type > s_unmountableFS(
 {
@@ -52,12 +53,13 @@ static QSet< FileSystem::Type > s_unmountableFS(
     FileSystem::Lvm2_PV
 } );
 
-CreatePartitionDialog::CreatePartitionDialog( Device* device, PartitionNode* parentPartition, QWidget* parentWidget )
+CreatePartitionDialog::CreatePartitionDialog( Device* device, PartitionNode* parentPartition, const QStringList& usedMountPoints, QWidget* parentWidget )
     : QDialog( parentWidget )
     , m_ui( new Ui_CreatePartitionDialog )
     , m_partitionSizeController( new PartitionSizeController( this ) )
     , m_device( device )
     , m_parent( parentPartition )
+    , m_usedMountPoints( usedMountPoints )
 {
     m_ui->setupUi( this );
     m_ui->encryptWidget->setText( tr( "En&crypt" ) );
@@ -101,6 +103,8 @@ CreatePartitionDialog::CreatePartitionDialog( Device* device, PartitionNode* par
     connect( m_ui->fsComboBox, SIGNAL( activated( int ) ), SLOT( updateMountPointUi() ) );
     connect( m_ui->extendedRadioButton, SIGNAL( toggled( bool ) ), SLOT( updateMountPointUi() ) );
 
+    connect( m_ui->mountPointComboBox, &QComboBox::currentTextChanged, this, &CreatePartitionDialog::checkMountPointSelection );
+
     // Select a default
     m_ui->fsComboBox->setCurrentIndex( defaultFsIndex );
     updateMountPointUi();
@@ -252,6 +256,18 @@ CreatePartitionDialog::updateMountPointUi()
         m_ui->mountPointComboBox->setCurrentText( QString() );
 }
 
+void
+CreatePartitionDialog::checkMountPointSelection(const QString& selection)
+{
+    if (m_usedMountPoints.contains(selection)) {
+        m_ui->labelMountPoint->setText("Mountpoint already used. Please select another one.");
+        m_ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(false);
+    } else {
+        m_ui->labelMountPoint->setText( QString() );
+        m_ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(true);
+    }
+}
+
 void
 CreatePartitionDialog::initPartResizerWidget( Partition* partition )
 {

src/modules/partition/gui/CreatePartitionDialog.h

@@ -42,7 +42,7 @@ class CreatePartitionDialog : public QDialog
 {
     Q_OBJECT
 public:
-    CreatePartitionDialog( Device* device, PartitionNode* parentPartition, QWidget* parentWidget = nullptr );
+    CreatePartitionDialog( Device* device, PartitionNode* parentPartition, const QStringList& usedMountPoints, QWidget* parentWidget = nullptr );
     ~CreatePartitionDialog();
 
     /**
@@ -61,6 +61,7 @@ public:
 
 private Q_SLOTS:
     void updateMountPointUi();
+    void checkMountPointSelection(const QString &);
 
 private:
     void setupFlagsList();
@@ -69,6 +70,7 @@ private:
     Device* m_device;
     PartitionNode* m_parent;
     PartitionRole m_role = PartitionRole( PartitionRole::None );
+    QStringList m_usedMountPoints;
 
     void initGptPartitionTypeUi();
     void initMbrPartitionTypeUi();

src/modules/partition/gui/CreatePartitionDialog.ui

@@ -108,7 +108,7 @@
        <property name="sizeHint" stdset="0">
         <size>
          <width>20</width>
-         <height>12</height>
+         <height>13</height>
         </size>
        </property>
       </spacer>
@@ -126,6 +126,9 @@
      <item row="3" column="1">
       <widget class="QComboBox" name="fsComboBox"/>
      </item>
+     <item row="4" column="1">
+      <widget class="EncryptWidget" name="encryptWidget" native="true"/>
+     </item>
      <item row="5" column="1">
       <spacer name="verticalSpacer_2">
        <property name="orientation">
@@ -162,14 +165,26 @@
        </property>
       </widget>
      </item>
-     <item row="7" column="0">
+     <item row="7" column="1">
+      <widget class="QLabel" name="labelMountPoint">
+       <property name="font">
+        <font>
+         <italic>true</italic>
+        </font>
+       </property>
+       <property name="text">
+        <string/>
+       </property>
+      </widget>
+     </item>
+     <item row="8" column="0">
       <widget class="QLabel" name="label_3">
        <property name="text">
         <string>Flags:</string>
        </property>
       </widget>
      </item>
-     <item row="7" column="1">
+     <item row="8" column="1">
       <widget class="QListWidget" name="m_listFlags">
        <property name="alternatingRowColors">
         <bool>true</bool>
@@ -182,7 +197,7 @@
        </property>
       </widget>
      </item>
-     <item row="8" column="0">
+     <item row="9" column="0">
       <spacer name="verticalSpacer">
        <property name="orientation">
         <enum>Qt::Vertical</enum>
@@ -195,9 +210,6 @@
        </property>
       </spacer>
      </item>
-     <item row="4" column="1">
-      <widget class="EncryptWidget" name="encryptWidget" native="true"/>
-     </item>
     </layout>
    </item>
    <item>

src/modules/partition/gui/PartitionPage.cpp

@@ -176,7 +176,7 @@ PartitionPage::onCreateClicked()
     Partition* partition = model->partitionForIndex( index );
     Q_ASSERT( partition );
 
-    QPointer<CreatePartitionDialog> dlg = new CreatePartitionDialog( model->device(), partition->parent(), this );
+    QPointer<CreatePartitionDialog> dlg = new CreatePartitionDialog( model->device(), partition->parent(), getCurrentUsedMountpoints(), this );
     dlg->initFromFreeSpace( partition );
     if ( dlg->exec() == QDialog::Accepted )
     {
@@ -265,7 +265,7 @@ PartitionPage::onPartitionViewActivated()
 void
 PartitionPage::updatePartitionToCreate( Device* device, Partition* partition )
 {
-    QPointer<CreatePartitionDialog> dlg = new CreatePartitionDialog( device, partition->parent(), this );
+    QPointer<CreatePartitionDialog> dlg = new CreatePartitionDialog( device, partition->parent(), getCurrentUsedMountpoints(), this );
     dlg->initFromPartitionToCreate( partition );
     if ( dlg->exec() == QDialog::Accepted )
     {
@@ -375,3 +375,22 @@ PartitionPage::updateBootLoaderIndex()
         m_ui->bootLoaderComboBox->setCurrentIndex( m_lastSelectedBootLoaderIndex );
     }
 }
+
+QStringList
+PartitionPage::getCurrentUsedMountpoints()
+{
+    QModelIndex index = m_core->deviceModel()->index( m_ui->deviceComboBox->currentIndex(), 0 );
+    if ( !index.isValid() )
+        return QStringList();
+
+    Device* device = m_core->deviceModel()->deviceForIndex( index );
+    QStringList mountPoints;
+
+    for (Partition* partition : device->partitionTable()->children()) {
+        if (!partition->mountPoint().isEmpty()) {
+            mountPoints << partition->mountPoint();
+        }
+    }
+
+    return mountPoints;
+}

src/modules/partition/gui/PartitionPage.h

@@ -62,6 +62,8 @@ private:
     void updateFromCurrentDevice();
     void updateBootLoaderIndex();
 
+    QStringList getCurrentUsedMountpoints();
+
     QMutex m_revertMutex;
     int    m_lastSelectedBootLoaderIndex;
 };