pt-show-grants broken on MariaDB 10.x

[Andrew Garner]

$ wget percona.com/get/pt-show-grants

$ perl pt-show-grants --version
pt-show-grants 2.2.19

$ perl pt-show-grants
-- Grants dumped by pt-show-grants
-- Dumped from server Localhost via UNIX socket, MySQL 10.1.17-MariaDB-1~jessie at 2016-09-02 03:43:12
Use of uninitialized value $create in substitution (s///) at pt-show-grants line 1937.

This seems to be due to applying the 5.7.6+ logic to MariaDB:

      if ( VersionCompare::cmp($version, '5.7.6') >= 0 ) {

Adjusting that check to avoid the -MariaDB case seems to work:

      if ( $version !~ "-MariaDB" && VersionCompare::cmp($version, '5.7.6') >= 0 ) {

$ perl pt-show-grants
-- Grants dumped by pt-show-grants
-- Dumped from server Localhost via UNIX socket, MySQL 10.1.17-MariaDB-1~jessie at 2016-09-02 03:50:53
-- Grants for 'root'@'localhost'
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED VIA unix_socket WITH GRANT OPTION;
GRANT PROXY ON ''@'%' TO 'root'@'localhost' WITH GRANT OPTION;

[Pim Rupert (prupert)]

This bug also affects all my MariaDB 10.1 installations. The following fix works:

```
1924c1924
< if ( VersionCompare::cmp($version, '5.7.6') >= 0 ) {
---
> if ( $version !~ "-MariaDB" && VersionCompare::cmp($version, '5.7.6') >= 0 ) {
```

[Gaëtan Trellu (goldyfruit)]

Same for me with the current versions:
  - percona-toolkit-2.2.19-1.noarch
  - MariaDB-server-10.1.17-1.el7.centos.x86_64

The workaround above works for me.

[Vide (vide80)]

I'm affected by this too. Another workaround is to revert to pt 2.2.16 (before #143537 fix was applied)

[Vide (vide80)]

Sorry, didn't see that there is another bug for this issue and that the fix is already committed there :(