SASS compiler throws error on valid filter lines

[vaadin-bot]

Originally by @tmattsso

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valid lines:

-ms-filter:"progid:DXImageTransform.Microsoft.Alpha"(Opacity=0);
filter: progid:DXImageTransform.Microsoft.Alpha(opacity=0);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f7f7f7', endColorstr='#e6e6e6',GradientType=0 )!important; / IE6-9 /

error message:
Dez 10, 2015 9:16:36 AM com.vaadin.sass.internal.handler.SCSSErrorHandler log
SEVERE: Error when parsing file
/workspace/ui-framework-vaadin/src/main/webapp/VAADIN/themes/mytheme/_plentymarkets.scss on line 17755, column 16
Dez 10, 2015 9:16:36 AM com.vaadin.sass.internal.handler.SCSSErrorHandler log
SEVERE: encountered "(". Was expecting one of: "=" "," ";" "." ")" "and" "or" "not" ":" "#{" "to" "through" "in" "from" <NOT_FUNCTION>

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Imported from https://dev.vaadin.com/ issue #19356

[mvysny]

We apologize for the lack of progress in this area. This could be related to the fact that Vaadin uses SASS compiler that is forked from a old version.

There is old blog post on how to use SASS 3 with Vaadin 8. If I remember correctly, it is not 100% backwards compatible, thus it was not taken into Vaadin itself.

Please see vaadin/framework#8339 for more details; the example project with experimental SASS 3 compiler can be found here: https://github.com/pleku/vaadin-libsass