From f06b63bc66ad4ed3e8425e71f277c8ad9942bf3c Mon Sep 17 00:00:00 2001
From: Martin Kleusberg <mkleusberg@gmail.com>
Date: Sun, 14 May 2017 20:21:05 +0200
Subject: [PATCH] Use savepoint in Edit Index dialog

Create a save point when opening the Edit Index dialog. This allows us
to revert back to the last version when pressing the Cancel button.
---
 src/EditIndexDialog.cpp | 16 ++++++++++++++--
 src/EditIndexDialog.h   |  3 +++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/EditIndexDialog.cpp b/src/EditIndexDialog.cpp
index 085b3301..6591cf12 100644
--- a/src/EditIndexDialog.cpp
+++ b/src/EditIndexDialog.cpp
@@ -11,7 +11,8 @@ EditIndexDialog::EditIndexDialog(DBBrowserDB& db, const QString& indexName, bool
       curIndex(indexName),
       index(indexName),
       newIndex(createIndex),
-      ui(new Ui::EditIndexDialog)
+      ui(new Ui::EditIndexDialog),
+      m_sRestorePointName(pdb.generateSavepointName("editindex"))
 {
     // Create UI
     ui->setupUi(this);
@@ -52,6 +53,9 @@ EditIndexDialog::EditIndexDialog(DBBrowserDB& db, const QString& indexName, bool
     } else {
         tableChanged(ui->comboTableName->currentText(), false);
     }
+
+    // Create a savepoint to revert back to
+    pdb.setSavepoint(m_sRestorePointName);
 }
 
 EditIndexDialog::~EditIndexDialog()
@@ -211,7 +215,7 @@ void EditIndexDialog::accept()
     // When editing an index, delete the old one first
     if(!newIndex)
     {
-        if(!pdb.executeSQL(QString("DROP INDEX %1;").arg(sqlb::escapeIdentifier(curIndex))))
+        if(!pdb.executeSQL(QString("DROP INDEX IF EXISTS %1;").arg(sqlb::escapeIdentifier(curIndex))))
         {
             QMessageBox::warning(this, qApp->applicationName(), tr("Deleting the old index failed:\n%1").arg(pdb.lastError()));
             return;
@@ -225,6 +229,14 @@ void EditIndexDialog::accept()
         QMessageBox::warning(this, QApplication::applicationName(), tr("Creating the index failed:\n%1").arg(pdb.lastError()));
 }
 
+void EditIndexDialog::reject()
+{
+    // Rollback to our savepoint
+    pdb.revertToSavepoint(m_sRestorePointName);
+
+    QDialog::reject();
+}
+
 void EditIndexDialog::updateSqlText()
 {
     ui->sqlTextEdit->setText(index.sql());
diff --git a/src/EditIndexDialog.h b/src/EditIndexDialog.h
index 574a6d66..a055da0b 100644
--- a/src/EditIndexDialog.h
+++ b/src/EditIndexDialog.h
@@ -22,6 +22,8 @@ public:
 
 private slots:
     void accept();
+    void reject();
+
     void tableChanged(const QString& new_table, bool initialLoad = false);
     void checkInput();
     void addToIndex(const QModelIndex& idx = QModelIndex());
@@ -33,6 +35,7 @@ private:
     sqlb::Index index;
     bool newIndex;
     Ui::EditIndexDialog* ui;
+    QString m_sRestorePointName;
 
     void updateColumnLists();
     void updateSqlText();