Autoprefixer removig blank lines

[hydandata]

Selecting "Add Missing Standard Properties" or "Add Missing Vendor Specifics" from Web Essentials context menu causes empty lines to be removed from the containing definition, even when no changes are required. For example:

Before:

.row {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;

    -ms-flex-wrap: wrap;
    flex-wrap: wrap;

    -ms-flex: 0 1 auto;
    flex: 0 1 auto;
}

After:

.row {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -ms-flex-wrap: wrap;
    flex-wrap: wrap;   
    -ms-flex: 0 1 auto;
    flex: 0 1 auto;
}

[am11]

Note: Autoprefixer is the name of a node.js based service which WE kicks in when we compile Less or Sass files (given the respective option in WE Options > CSS is enabled) and Add missing .. et al. are WE's own commands/features.

The responsible code lives here: CssAddMissingStandardCommandTarget.cs#L65-L85, but more interestingly, there is another bug, that is; this condition should not be satisfied with your example in first place and hence overwrite the buffer (since your code already has all the vendor specifics). I think we need to revisit the visitor code. :)