...

src/calibre/gui2/__init__.py

@@ -205,11 +205,14 @@ def error_dialog(parent, title, msg, det_msg='', show=False,
         return d.exec_()
     return d
 
-def question_dialog(parent, title, msg, det_msg=''):
+def question_dialog(parent, title, msg, det_msg='', show_copy_button=True):
     d = MessageBox(QMessageBox.Question, title, msg, QMessageBox.Yes|QMessageBox.No,
                     parent, det_msg)
     d.setIconPixmap(QPixmap(I('dialog_information.svg')))
     d.setEscapeButton(QMessageBox.No)
+    if not show_copy_button:
+        d.cb.setVisible(False)
+
     return d.exec_() == QMessageBox.Yes
 
 def info_dialog(parent, title, msg, det_msg='', show=False):

src/calibre/gui2/dialogs/config/__init__.py

@@ -656,7 +656,7 @@ class ConfigDialog(ResizableDialog, Ui_Dialog):
                     _('The selected column is not a custom column'), show=True)
         if not question_dialog(self, _('Are you sure?'),
             _('Do you really want to delete column %s and all its data?') %
-            self.custcols[col]['name']):
+            self.custcols[col]['name'], show_copy_button=False):
             return
         self.columns.item(idx).setCheckState(False)
         self.columns.takeItem(idx)

src/calibre/gui2/dialogs/config/create_custom_column.ui

@@ -20,7 +20,7 @@
    </sizepolicy>
   </property>
   <property name="windowTitle">
-   <string>Create a custom column</string>
+   <string>Create or edit custom columns</string>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
@@ -126,7 +126,7 @@
         </font>
        </property>
        <property name="text">
-        <string>Create and edit custom columns</string>
+        <string>Create or edit custom columns</string>
        </property>
       </widget>
      </item>