[patch] ee segfaults when jumping to line zero

hi there,

could somebody please commit the attached patch to HEAD and mfc it asap? it's
a no brainer. ee inits a *char with NULL and accesses it before the *char is
being initialised properly.

to repeat:

1)start `ee'
2)press `ctrl+c'
3)enter `0' =====>>> BAM!!!

this will occur under all branches running ee 1.5.0. the problem might also
occur in branches with previous versions of ee. i think only 6-stable is still
using the 1.4.X ee release.

the patch was submitted by Fredrik Lindberg in bin/137707, but sadly nobody
paid attention to it. :(

this fix should also be forwarded to re_at_ asap so we can have it in
8.0-RELEASE.

alex