Add a button to open the config file in a text editor

src/qt/forms/optionsdialog.ui

@@ -691,6 +691,21 @@
    </item>
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout_Buttons">
+     <item>
+      <layout class="QVBoxLayout" name="verticalLayout_Buttons">
+       <item>
+        <widget class="QPushButton" name="openBitcoinConfButton">
+         <property name="toolTip">
+          <string>Open the %1 configuration file from the working directory.</string>
+         </property>
+         <property name="text">
+          <string>Open Configuration File</string>
+         </property>
+         <property name="autoDefault">
+          <bool>false</bool>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="QPushButton" name="resetButton">
          <property name="toolTip">
@@ -704,6 +719,8 @@
          </property>
         </widget>
        </item>
+      </layout>
+     </item>
      <item>
       <spacer name="horizontalSpacer_1">
        <property name="orientation">
@@ -755,6 +772,23 @@
        </property>
       </spacer>
      </item>
+     <item>
+      <layout class="QVBoxLayout" name="verticalLayout_4">
+       <item>
+        <spacer name="verticalSpacer">
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>40</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <layout class="QHBoxLayout" name="horizontalLayout">
          <item>
           <widget class="QPushButton" name="okButton">
            <property name="text">
@@ -781,6 +815,10 @@
         </layout>
        </item>
       </layout>
+     </item>
+    </layout>
+   </item>
+  </layout>
  </widget>
  <customwidgets>
   <customwidget>

src/qt/guiutil.cpp

@@ -417,6 +417,22 @@ void openDebugLogfile()
         QDesktopServices::openUrl(QUrl::fromLocalFile(boostPathToQString(pathDebug)));
 }
 
+bool openBitcoinConf()
+{
+    boost::filesystem::path pathConfig = GetConfigFile(BITCOIN_CONF_FILENAME);
+
+    /* Create the file */
+    boost::filesystem::ofstream configFile(pathConfig, std::ios_base::app);
+    
+    if (!configFile.good())
+        return false;
+    
+    configFile.close();
+    
+    /* Open bitcoin.conf with the associated application */
+    return QDesktopServices::openUrl(QUrl::fromLocalFile(boostPathToQString(pathConfig)));
+}
+
 void SubstituteFonts(const QString& language)
 {
 #if defined(Q_OS_MAC)

src/qt/guiutil.h

@@ -114,6 +114,9 @@ namespace GUIUtil
     // Open debug.log
     void openDebugLogfile();
 
+    // Open the config file
+    bool openBitcoinConf();
+
     // Replace invalid default fonts with known good ones
     void SubstituteFonts(const QString& language);
 

src/qt/optionsdialog.cpp

@@ -232,6 +232,18 @@ void OptionsDialog::on_resetButton_clicked()
     }
 }
 
+void OptionsDialog::on_openBitcoinConfButton_clicked()
+{
+    /* explain the purpose of the config file */
+    QMessageBox::information(this, tr("Configuration options"),
+        tr("The configuration file is used to specify advanced user options which override GUI settings. "
+           "Additionally, any command-line options will override this configuration file."));
+
+    /* show an error if there was some problem opening the file */
+    if (!GUIUtil::openBitcoinConf())
+        QMessageBox::critical(this, tr("Error"), tr("The configuration file could not be opened."));
+}
+
 void OptionsDialog::on_okButton_clicked()
 {
     mapper->submit();

src/qt/optionsdialog.h

@@ -47,6 +47,7 @@ private Q_SLOTS:
     /* set OK button state (enabled / disabled) */
     void setOkButtonState(bool fState);
     void on_resetButton_clicked();
+    void on_openBitcoinConfButton_clicked();
     void on_okButton_clicked();
     void on_cancelButton_clicked();