[poppler] Issue with transparent form elements

[Milan Vancura]

On Tue 10-02-15 17:32:01, Petr Gajdos wrote:
> we are experiencing the issue with rendering of form elements of the
> type:
> 
> 382 0 obj
> <<
> /Type /Annot
> [...]
> /MK <<
> /BC [ ]
> /BG [ ]
> >>
> [...]
> endobj
> 
> Such elements are displayed black with e. g. gimp, evince and okular.

Hello,

I just add some details: according to the PDF 1.7 specification, chapter
Annotations -> Widget Annotations, table 8.40, the value of either /BG or /BC
attributes of /MK dictionary is an Array of this definition:

. (Optional) An array of numbers in the range 0.0 to 1.0 specifying the color of
. the widget annotation’s border. The number of array elements determines the
. color space in which the color is defined:
. 	0 No color; transparent
. 	1 DeviceGray
. 	3 DeviceRGB
. 	4 DeviceCMYK


The support for '0' variant is missing in libpoppler and Petr's patch fixes
that.

Milan