Merge pull request #6692 from blink1073/qtconsole-completion

Improve handling of cursor_start and cursor_end for QtConsole completions.

IPython/qt/console/ipython_widget.py

@@ -151,8 +151,23 b' class IPythonWidget(FrontendWidget):'
             start = content['cursor_start']
             end = content['cursor_end']
             
+            start = max(start, 0)
+            end = max(end, start + 1)
+
+            # Move the control's cursor to the desired end point
+            cursor_pos = self._get_input_buffer_cursor_pos()
+            if end < cursor_pos:
+                cursor.movePosition(QtGui.QTextCursor.Left,
+                                    n=(cursor_pos - end))
+            elif end > cursor_pos:
+                cursor.movePosition(QtGui.QTextCursor.Right,
+                                    n=(end - cursor_pos))
+            # This line actually applies the move to control's cursor
+            self._control.setTextCursor(cursor)
+
             offset = end - start
-            # Move the cursor to the start of the match and complete.
+            # Move the local cursor object to the start of the match and
+            # complete.
             cursor.movePosition(QtGui.QTextCursor.Left, n=offset)
             self._complete_with_items(cursor, matches)