some buglet in gnulib-tool func_update_ignorelist

[Ralf Wildenhues]

Hello,

I haven't been able to track this one down, because it was a one-time
failure only, and I didn't have a backup of the tree before the command.
Anyway, bootstrap on the branch-1.4 branch of M4 showed this sed error
during 'gnulib-tool --update', with a dirty gnulib tree from last week:

Updating file build-aux/announce-gen (backup in build-aux/announce-gen~)
Updating file build-aux/gnupload (backup in build-aux/gnupload~)
Updating file lib/binary-io.h (backup in lib/binary-io.h~)
[...]
Updating file lib/sys_time.in.h (backup in lib/sys_time.in.h~)
Updating file lib/unistd.in.h (backup in lib/unistd.in.h~)
Updating file m4/assert.m4 (backup in m4/assert.m4~)
[...]
Updating file m4/stdlib_h.m4 (backup in m4/stdlib_h.m4~)
Updating file tests/test-lock.c (backup in tests/test-lock.c~)
Updating file tests/test-tls.c (backup in tests/test-tls.c~)
Updating lib/Makefile.am (backup in lib/Makefile.am~)
Updating m4/gnulib-comp.m4 (backup in m4/gnulib-comp.m4~)
Updating tests/Makefile.am (backup in tests/Makefile.am~)
Updating ./doc/.cvsignore (backup in ./doc/.cvsignore~)
Updating ./doc/.gitignore (backup in ./doc/.gitignore~)
sed: file /dev/shm/ralf/tmp/glZ19707/sed-ignore-removed line 2: unknown 
command: `f'
Updating ./lib/.gitignore (backup in ./lib/.gitignore~)
Updating ./m4/.cvsignore (backup in ./m4/.cvsignore~)
Updating ./m4/.gitignore (backup in ./m4/.gitignore~)
Updating ./tests/.gitignore (backup in ./tests/.gitignore~)
Finished.


It looks to me like the creation of the "$tmp"/sed-ignore-removed script
in func_update_ignorelist needs more escaping, e.g., all characters that
are special within a sed '/BRE/' address specification: '[', ']', '/',
'*', '\', '.', '{', '}', '^', '$'.  I don't quite get how the above
could have happened though, m4/doc doesn't seem to contain files with
weird names, so I'm assuming I'm missing something.

Thanks,
Ralf