ada-mode: Project Editor not working

[Florian Weimer]

In GNU Emacs 21.2.1 (i686-pc-linux-gnu)
 of 2002-03-23 on deneb
configured using `configure  --prefix=/opt/emacs'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: C
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

In an ada-mode buffer, press 'C-c u'.  The project file buffer opens.
Switch to the "Switches" tab, and you'll get an "Overlapping fields"
error message.

A backtrace:

Debugger entered--Lisp error: (error "Overlapping fields")
  signal(error ("Overlapping fields"))
  error("Overlapping fields")
  widget-field-find(276)
  widget-after-change(276 279 0)
  move-to-column(54 t)
  ada-prj-field(comp_opt "Switches for the compiler" "These switches are used 
in the default\ncompilation commands, both for compiling a\nsingle file and 
rebuilding the whole project")
  ada-prj-display-page(3)
  #[(&rest dummy) "ÀÁ!‡" [ada-prj-display-page 3] 2]((push-button :args nil 
:value "Switches" :notify #[(&rest dummy) "ÀÁ!‡" [ada-prj-display-page 3] 2] 
:button-overlay #<overlay from 279 to 1 in *Customize Ada Mode*> :from #<marker 
(before-insertion) at 279 in *Customize Ada Mode*> :to #<marker at 1 in 
*Customize Ada Mode*>) (push-button :args nil :value "Switches" :notify 
#[(&rest dummy) "ÀÁ!‡" [ada-prj-display-page 3] 2] :button-overlay #<overlay 
from 279 to 1 in *Customize Ada Mode*> :from #<marker (before-insertion) at 279 
in *Customize Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) nil)
  widget-apply((push-button :args nil :value "Switches" :notify #[(&rest dummy) 
"ÀÁ!‡" [ada-prj-display-page 3] 2] :button-overlay #<overlay from 279 to 1 in 
*Customize Ada Mode*> :from #<marker (before-insertion) at 279 in *Customize 
Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) :notify (push-button 
:args nil :value "Switches" :notify #[(&rest dummy) "ÀÁ!‡" 
[ada-prj-display-page 3] 2] :button-overlay #<overlay from 279 to 1 in 
*Customize Ada Mode*> :from #<marker (before-insertion) at 279 in *Customize 
Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) nil)
  widget-item-action((push-button :args nil :value "Switches" :notify #[(&rest 
dummy) "ÀÁ!‡" [ada-prj-display-page 3] 2] :button-overlay #<overlay from 279 to 
1 in *Customize Ada Mode*> :from #<marker (before-insertion) at 279 in 
*Customize Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) nil)
  widget-apply((push-button :args nil :value "Switches" :notify #[(&rest dummy) 
"ÀÁ!‡" [ada-prj-display-page 3] 2] :button-overlay #<overlay from 279 to 1 in 
*Customize Ada Mode*> :from #<marker (before-insertion) at 279 in *Customize 
Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) :action nil)
  widget-apply-action((push-button :args nil :value "Switches" :notify #[(&rest 
dummy) "ÀÁ!‡" [ada-prj-display-page 3] 2] :button-overlay #<overlay from 279 to 
1 in *Customize Ada Mode*> :from #<marker (before-insertion) at 279 in 
*Customize Ada Mode*> :to #<marker at 1 in *Customize Ada Mode*>) nil)
  widget-button-press(150)
  call-interactively(widget-button-press)