NPE @ sun.awt.font.AdvanceCache.get(AdvanceCache.java:135)

We have seen our NETSMART client run into paint issues (one
particular component becoming unusable - requiring a restart of the
client) due to a NullPointerException thrown from java internals.
This problem has recently been seen by our test team atleast twice and
they have raised fix priority on this.

java.lang.NullPointerException
        at sun.awt.font.AdvanceCache.get(AdvanceCache.java:135)
        at java.awt.font.TextLayout$OptInfo.getAdvance(TextLayout.java:248)
        at java.awt.font.TextLayout$OptInfo.getLogicalBounds(TextLayout.java:261)
        at sun.awt.font.Decoration$DecorationImpl.drawTextAndEmbellishments(Decoration.java:243)
        at sun.awt.font.Decoration$DecorationImpl.drawTextAndDecorations(Decoration.java:273)
        at java.awt.font.TextLayout$OptInfo.draw(TextLayout.java:298)
        at java.awt.font.TextLayout.draw(TextLayout.java:2660)
        at sun.java2d.SunGraphics2D.drawString(SunGraphics2D.java:2595)
In a related problem on 1.4.2 when the cache is flushed, the variable 'i' is not reset
but can still be used as described in incident 709901

java.lang.ArrayIndexOutOfBoundsException: 1321
        at sun.awt.font.AdvanceCache.get(AdvanceCache.java:168)
        at java.awt.font.TextLayout
$OptInfo.handleGetVisualBounds(Unknown Source)
        at sun.awt.font.Decoration.getVisualBounds(Decoration.java:105)
        at java.awt.font.TextLayout$OptInfo.getVisualBounds(Unknown
Source)
        at java.awt.font.TextLayout.getBounds(Unknown Source)
        ...

the submitter pointed out that
cacheNum = 0;
should become
i = cacheNum = 0;