git-version-gen: allow 'snapshot' as .tarball-version contents

[Bruno Haible]

Hi,

git-version-gen currently rejects some forms of .tarball-version:

$ cat > .tarball-version
20191011
$ build-aux/git-version-gen .tarball-version; echo
20191011
$ cat > .tarball-version
snapshot
$ build-aux/git-version-gen .tarball-version; echo
build-aux/git-version-gen: WARNING: .tarball-version is missing or damaged
UNKNOWN

I need a non-numeric version for continuous publishing of gettext snapshot
tarballs, and I want the tarballs to be called gettext-snapshot.tar.gz,
not gettext-UNKNOWN.tar.gz.

This patch fixes the problem.


2019-10-13  Bruno Haible  <br...@clisp.org>

        git-version-gen: Allow 'snapshot' as .tarball-version contents.
        * build-aux/git-version-gen: Don't map non-numeric .tarball-version
        contents to the empty string.

diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index 45b5656..d855645 100755
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -142,11 +142,9 @@ then
     v=`cat $tarball_version_file` || v=
     case $v in
         *$nl*) v= ;; # reject multi-line output
-        [0-9]*) ;;
-        *) v= ;;
     esac
     test "x$v" = x \
-        && echo "$0: WARNING: $tarball_version_file is missing or damaged" 1>&2
+        && echo "$0: WARNING: $tarball_version_file is damaged" 1>&2
 fi
 
 if test "x$v" != x