Hi,

I have observed this problem in the sh-elf configuration of GDB. It is 
not visible in the i686-linux configuration because it uses the 
following union in a different way.

/* Structure describing source line or line address */
union tui_line_or_address
{
   int line_no;
   CORE_ADDR addr;
};


The problem is that the union is always compared using 'addr'. In the 
case where it was set using 'line_no', as it is in sh-elf, half the 
union contains garbage. This appears to be killing the comparison in 
tui_set_is_exec_point_at() in tui-winsource.c.

The result is that the current line is never highlighted as it should 
be. I assume the reason it works on i686-linux is that that host/target 
uses the addr field rather than the line_no field.

The attached patch provides one way to fix the problem. I could not 
think of any way to fix the comparison because there is no way I can see 
to know which mode it is using, so I have changed the type of line_no in 
the union to match the type of addr. This does not seem to be the Right 
Thing to do with a union (because it might as well be one variable), but 
I can't see any other down side.

Andrew Stubbs