>>     When I trace a program step by step in GDB under Emacs,  Emacs will
>> switch the input focus to the source code.
>It doesn't for me.  Here the selected window remains the one where the
>GDB interaction happens.  Perhaps you could describe what you do in
>more detail, starting with "emacs -Q".
>Also, which version of Emacs is that?

> > I am using Emacs 23.3(9.0) in Mac OS 10.6.  This is the operation
> sequence
> > which causes the problem:
> > 1. start Emacs with -Q, open GDB under Emacs: gdb --annotate=3 program
> > 2. set the breakpoint:  b location
> > 3. run the program: r
> > 4. When GDB hits the breakpoint, the window splits horizontally into two
> > windows, one with GDB,
> >    another one is the source code,  at this time, the focus point is in
> GDB
> >  window.
> > 5. while the focus point stil remains in GDB window, open a new frame
> with
> >  : Ctrl-x 5 2.
> >     Now a new frame is created with one window and another GDB  is in it.
> > 6. Switch the focus point to source code window, Run delete other winodw:
> > Ctrl-X 1.
> >     Now the source code window occupies the whole frame which was
> > previously splited into two windows.
> >     Now Emacs has two frames. One frame has only  GDB window, another
> frame
> > has only source code window.
> >     Now, If I switch the focus point back to the GDB window, and keep
> > stepping using the GDB command "next", the focus
> >     point will switch back to source code window automatically after each
> > GDB command.

> I can confirm this behavior in both Emacs 23.3 and the current
> development sources.

> Please report this as a bug using "M-x report-emacs-bug RET", so that
> it will get fixed, preferably for the next version 24.3.