gschem fails with backtrace if the default-titleblock cannot be loaded

[KaiMartin]

I just had gschem from current git head fail on me with backtrace. The trigger was a wrong file name for the default-titlepage in gafrc. IIRC, half a year ago this situation was handled more gracefully. The GUI would start and show the familiar red warning sign.

To reproduce:

1) make sure, the default titleblock cannot be found. E.g. with this line in gschemrc:
(define default-titleblock "no_titleblock.sym")

2) start gschem
Instead of a GUI, there is a backtrace:

/---------------------------------------------
$ gschem

Backtrace:
In unknown file:
   ?: 0* [#<procedure {#f} (page)> #<geda-page 0x889f4c8>]
In /usr/local/share/gEDA/system-gschemrc:
 954: 1* (if (and # #) (add-component-at-xy page default-titleblock 40000 ...))
 962: 2 [add-component-at-xy #<geda-page 0x889f4c8> "title-block.sym" ...]
In /usr/local/share/gEDA/scheme/gschem/deprecated.scm:
   ...
 121: 3 (let* ((C #)) (page-append! page C) (run-hook add-objects-hook (cons C #)))
 124: 4* [page-append! #<geda-page 0x889f4c8> {#f}]
In /usr/local/share/gEDA/scheme/geda/page.scm:
  42: 5* [for-each #<procedure {#f} (x)> ({#f})]
In unknown file:
   ?: 6* [#<procedure {#f} (x)> {#f}]
In /usr/local/share/gEDA/scheme/geda/page.scm:
  42: 7* [%page-append! #<geda-page 0x889f4c8> {#f}]

/usr/local/share/gEDA/scheme/geda/page.scm:42:25: In procedure %page-append! in expression (%page-append! P x):
/usr/local/share/gEDA/scheme/geda/page.scm:42:25: Wrong type argument in position 2: #f
\------------------------------------

---<)kaimartin(>---

[Gareth Edwards (gareth-uk)]

In current git HEAD, I get the backtrace, but the GUI appears and the program appears to be fully functional. Low priority to fix this, I'd say.

[gpleda.org commit robot (gpleda-launchpad-robot)]

Bug was fixed by a commit
git master commit aaa25e5684a688e7186812d9cdd069ca88b3ea00
http://git.geda-project.org/geda-gaf/commit/?id=aaa25e5684a688e7186812d9cdd069ca88b3ea00

commit aaa25e5684a688e7186812d9cdd069ca88b3ea00
Author: Peter TB Brett <email address hidden>
Commit: Peter TB Brett <email address hidden>

    gschem: Deal with missing titleblock symbol gracefully.

    Closes-bug: lp-835855