gdb-ui and hl-line-mode

[Nick Roberts]

Eli Zaretskii writes:
 > Some people, when they debug a program, like to have the current line
 > in the source window to be clearly visible.  One way to do that in
 > Emacs is to turn on the hl-line-mode in the source buffer, but the
 > results are strange: if you step through the code when the source
 > window is the currently selected one, the highlighted line stays one
 > step behind the fringe arrow and the cursor (e.g., the arrow points to
 > line 10, whereas line 9 is highlighted); switching to another window
 > and back fixes the overlay position. 

Is this due to the fact GDB runs asynchronously i.e gud-call finishes
before the output of GDB is collected through gud-filter?

 >                                     And if you step with the source
 > window is not the selected one (e.g., you type `next' commands into
 > the GUD buffer), the highlight overlay does not move at all; however,
 > if you switch to the source window, the highlight overlay is correctly
 > moved to the current source line.

The commentary says:

;; Caveat: the buffer's point might be different from the point of a
;; non-selected window.

which presumably has something to do with point and window-point having
different values.

Nick