Inconsistent behavior for duplicate values

[delboni]

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 4.2.1
• Ruby: ruby 2.1.6p336 (2015-04-13 revision 50298) [x64-mingw32]
• Distribution: open source
• Module version: 2.3.0

How to reproduce (e.g Puppet code you use)

When ensure=present, if the variable meets the criteria, i.e., value exists (insert), exists in the beggining (prepend) or exists in the end (append), duplicates won't be removed even if they are present. E.g.:

ensure=present
value=d
mergemode=insert:  VAR="a;d;b;d;c"   => VAR="a;d;b;d;c"
mergemode=prepend: VAR="d;a;d;b;d;c" => VAR="d;a;d;b;d;c"
mergemode=append:  VAR="a;d;b;d;c;d" => VAR="a;d;b;d;c;d"

Duplicates will only be removed if the variable doesn't meet the criteria and its content needs to be re-written, such as in

ensure=present
value=d
mergemode=prepend: VAR="a;d;b;d;c" => VAR="d;a;b;c"
mergemode=append:  VAR="a;d;b;d;c" => VAR="a;b;c;d"

What are you seeing

The module behaviors according to the variable contents, so we never know the outcome for a given client.

What behaviour did you expect instead

I expected it to behave the same way, no matter what the variable content is. It should either keep all duplicates, just changing places as needed for append/prepend; OR always eliminate them.

As we have problems with duplicated paths in PATH, we would love to eliminate duplicates. A parameter that dictates the behavior may also be a solution.

Output log

Any additional information you'd like to impart