025 Import hangs on invalid scenegraph. This reproduces the problem:

    ----8<--- [snip] ---------8<--- [snip] ---------8<--- [snip] ---
    #VRML V2.0 utf8

    Group {
       children [
          *
       ]
    }
    ----8<--- [snip] ---------8<--- [snip] ---------8<--- [snip] ---

    The '*' character can be replaced by any character not valid in
    identifier names, and the bug will still be present.

    Should of course never hang, but rather spit out an error message
    and abort the import process.

    20020911 mortene.

    UPDATE 20050526 mortene: due to various fixes in SoInput-related
    code, the status for this bug has changed. Import no longer hangs,
    but fails -- as it should, but the first error message seems
    bogus:

    ----8<--- [snip] ---------8<--- [snip] ---------8<--- [snip] ---
    embla:~/tmp$ ./examinerviewer bug.wrl
    Coin read error: Expected '{'; got ']'
            Occurred at line   6 in bug.wrl
    Coin read error: Couldn't read value for field "children" of VRMLGroup
            Occurred at line   6 in bug.wrl
    ----8<--- [snip] ---------8<--- [snip] ---------8<--- [snip] ---
