bug#7827: Please do not give an error in help when it fails

bug#7827: Please do not give an error in help when it fails

[Lennart Borgman]

I just got this error when clicking the [back] button in help:

 Debugger entered--Lisp error: (error "Selecting deleted buffer")
  describe-mode(#<killed buffer>)
  apply(describe-mode #<killed buffer>)
  help-xref-go-back(#<buffer *Help*>)
  apply(help-xref-go-back #<buffer *Help*>)
  help-do-xref(214 help-xref-go-back (#<buffer *Help*>))
  help-button-action(#<marker (moves after insertion) at 1 in *Help*>)
  push-button(214)
  call-interactively(push-button nil nil)

That is very unpractical since it prevents from going further back in
the help stack. (Currently I am trying to find my test case which was
some help text 611 chars long, but I do not remember what it was.)

Just put the backtrace in the help buffer instead with a short explanation.

bug#7827: Please do not give an error in help when it fails

[Lars Ingebrigtsen]

Lennart Borgman <lennart.borgman@gmail.com> writes:

> I just got this error when clicking the [back] button in help:
>
>  Debugger entered--Lisp error: (error "Selecting deleted buffer")
>   describe-mode(#<killed buffer>)
>   apply(describe-mode #<killed buffer>)
>   help-xref-go-back(#<buffer *Help*>)
>   apply(help-xref-go-back #<buffer *Help*>)
>   help-do-xref(214 help-xref-go-back (#<buffer *Help*>))
>   help-button-action(#<marker (moves after insertion) at 1 in *Help*>)
>   push-button(214)
>   call-interactively(push-button nil nil)
>
> That is very unpractical since it prevents from going further back in
> the help stack. (Currently I am trying to find my test case which was
> some help text 611 chars long, but I do not remember what it was.)
>
> Just put the backtrace in the help buffer instead with a short explanation.

I don't see why an error in the help buffer should be treated
differently than anywhere else: If you have debug-on-error bound, then
you should get a proper backtrace. 

So I'm closing this bug report.

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   bloggy blog: http://lars.ingebrigtsen.no