[OpenJDK 2D-Dev] Review request for JDK-8054638 xrender: text drawn after setColor(Color.white) is actually black

[Clemens Eisserer]

Hello,

Please review my fix for JDK-8054638  xrender: text drawn after
setColor(Color.white) is actually black.

The XRSolidSrcPict manages a small 1x1 pixmap which is used as source
surface for some operations.
To avoid redundant fillRect operations when setting it's color, the
currently set pixel value is stored in an integer variable and
compared against each before the managed pixmap is used.
This integer variable was initially set to -1, which corresponds to
white - while the actual pixmap had been initialized to black in the
constructor - causing white text to be painted black under some
circumstances.

The fix corrently initializes the variable used for validation to solid black.

Thank you in advance, Clemens