Pressing Enter now always executes when the input buffer has one line.

IPython/core/usage.py

@@ -306,9 +306,8 b' once you learn a few basic keybindings it will be a much more efficient'
 environment.
 
 For single expressions or indented blocks, the console behaves almost like the
-terminal IPython: single expressions are immediately evaluated *if the cursor
-is at the end of the line*, and indented blocks are evaluated once a single
-blank line is entered::
+terminal IPython: single expressions are immediately evaluated, and indented
+blocks are evaluated once a single blank line is entered::
 
     In [1]: print "Hello IPython!"  # Enter was pressed at the end of the line
     Hello IPython!
@@ -318,12 +317,6 b' blank line is entered::'
        ...: 	
     0 1 2 3 4 5 6 7 8 9
 
-If you have a single expression and you go back to edit something in the
-beginning, hitting ``Enter`` will split the line (like a text editor) instead
-of executing it.  To execute, you can either go to the end of the line to hit
-``Enter``, or hit ``Shift-Enter`` anywhere, which is the 'force execution'
-keybinding.
-
 If you want to enter more than one expression in a single input block
 (something not possible in the terminal), you can use ``Control-Enter`` at the
 end of your first line instead of ``Enter``.  At that point the console goes

IPython/frontend/qt/console/console_widget.py

@@ -806,13 +806,16 b' class ConsoleWidget(Configurable, QtGui.QWidget):'
                     if self._reading_callback:
                         self._reading_callback()
 
-                # If there is only whitespace after the cursor, execute.
-                # Otherwise, split the line with a continuation prompt.
+                # If the input buffer is a single line or there is only
+                # whitespace after the cursor, execute. Otherwise, split the
+                # line with a continuation prompt.
                 elif not self._executing:
                     cursor.movePosition(QtGui.QTextCursor.End,
                                         QtGui.QTextCursor.KeepAnchor)
                     at_end = cursor.selectedText().trimmed().isEmpty() 
-                    if (at_end or shift_down) and not ctrl_down:
+                    single_line = (self._get_end_cursor().blockNumber() ==
+                                   self._get_prompt_cursor().blockNumber())
+                    if (at_end or shift_down or single_line) and not ctrl_down:
                         self.execute(interactive = not shift_down)
                     else:
                         # Do this inside an edit block for clean undo/redo.