[tools] Fix git-vault-export to read symbolic link names with spaces.…

… Fixes JB#35155

If a file name in the backup has a space, the link is currently
expanded without quotation marks, causing the readlink operation to
fail, thus causing the file to be added to the backup as a symbolic
link rather than a hard link, and thus the file is not actually
added to the backup.

tools/git-vault-export

@@ -36,15 +36,15 @@ GIT_DIR=$(pwd)
 
 find $DST -type l | grep '/blobs/' | while read -r LINK
 do
-    NAME=$(readlink $LINK)
+    NAME=$(readlink "$LINK")
     # match minimal relative blob ref (path inside the tree is unit/blobs/link)
     if [[ $NAME =~ \.\./\.\./\.git/blobs/ ]]; then
         FNAME=$(basename $NAME)
         DNAME="$GIT_DIR/.git/blobs/$(basename $(dirname $NAME))"
         [ -d $DNAME ] || error "There is no blob dir $DNAME for $LINK"
         FNAME="$DNAME/$FNAME"
         [ -f $FNAME ] || error "There is no blob file $FNAME for $LINK"
-        unlink $LINK || error "Can't unlink $LINK"
-        cp $FNAME $LINK || error "Can't copy $FNAME to $LINK"
+        unlink "$LINK" || error "Can't unlink $LINK"
+        cp $FNAME "$LINK" || error "Can't copy $FNAME to $LINK"
     fi
 done