Incorrect hard link counts in mirror_metadata file

[rknichols]

In rdiff-backup 1.4.0b1.dev4+gd9977cf, when new links are added to an existing group of hard linked files, the files that were originally in the group will not get an updated NumHardLinks count in the mirror_metadata file. Test script:

#!/bin/bash
mkdir tdir
echo something >tdir/File-00
for N in 10 20 30; do ln tdir/File-00 tdir/File-$N;done
rdiff-backup -b tdir tdir-bkup
sleep 2
for N in 15 25 26 ;do ln tdir/File-00 tdir/File-$N;done
ls -l tdir
rdiff-backup -b tdir tdir-bkup
cd tdir-bkup/rdiff-backup-data
New=$(ls mirror_metadata* | tail -1)
zgrep -E '^File|NumHardLinks|Inode' $New

Result:

# bash  ~/rblinktest 
total 28
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-00
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-10
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-15
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-20
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-25
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-26
-rw-r--r--. 7 root root 10 Jan 17 22:05 File-30
File .
File File-00
  NumHardLinks 4
  Inode 917506
File File-10
  NumHardLinks 4
  Inode 917506
File File-15
  NumHardLinks 7
  Inode 917506
File File-20
  NumHardLinks 4
  Inode 917506
File File-25
  NumHardLinks 7
  Inode 917506
File File-26
  NumHardLinks 7
  Inode 917506
File File-30
  NumHardLinks 4
  Inode 917506
#

Only the newly added files have the correct NumHardLinks count. The files in the mirror are correctly linked.

[zjw]

I've submitted pull request #240 to resolve this issue.