bug#6293: git-version-gen: Add support for a git tag transformation sed script

[Jim Meyering]

Eric Blake wrote:

> On 05/28/2010 09:00 AM, Jim Meyering wrote:
>> Or better still, don't use echo at all, in case
>> some tag starts with "-":
>>
>> -    && v=`echo $v | sed "$tag_sed_script"` \
>> +    && v=`printf %s "$v" | sed "$tag_sed_script"` \
>
> Some sed required the trailing newline; you need to use:
>
> v=`printf %s\\n "$v" | sed "$tag_sed_script"`

Good point.  Thanks.
Adjusted via this:

diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index 25753a3..9b821e0 100755
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -98,7 +98,7 @@ then
 elif test -d .git \
     && v=`git describe --abbrev=4 --match='v*' HEAD 2>/dev/null \
          || git describe --abbrev=4 HEAD 2>/dev/null` \
-    && v=`printf %s "$v" | sed "$tag_sed_script"` \
+    && v=`printf '%s\n' "$v" | sed "$tag_sed_script"` \
     && case $v in
         v[0-9]*) ;;
         *) (exit 1) ;;