Zero-width glyph is not handled correctly immediately after font change.

Name: vuR10080 Date: 08/30/2001

###@###.### 2001-08-30

I'm filing this on behalf of "Edward J. Garrett" <###@###.###>
as I have a personal interest in this too ;).

Here's an exerpt from his private email (emphasis mine).

| I began learning java last fall and have now written several pieces
| of java software, including:
|
| - a text-editor for typing Tibetan using a Wylie input method. This
| uses Tony Duff's new TibetanMachineWeb fonts, a version of his
| TibetanMachine fonts which is cross-platform because it only uses
| the lower half of ASCII.
[...]
| TibetanMachineWeb consists of ten fonts, and therefore my program has
| to do a lot of font changing. Often, in fact, a vowel requires a font
| change from the character that precedes it. But herein lies the
| problem: EXTRA SPACE IS INSERTED BEFORE A ZERO-WIDTH CHARACTER (like a
| vowel) WHEN IT REQUIRES A FONT CHANGE FROM THE PREVIOUS GLYPH. This
| problem afflicts versions 1.3.0-02 and above of the jdk, so basically
| we are frozen at 1.3.0-01 until the problem is fixed.

1.3.0-02 indeed introduced this problem. But at the time 1.4 public
beta (b74) was just released and I tried his test case on it and it
was ok. But now he contacted me again as beta2 reintroduced this bug.
Indeed, while b74 is ok, but b75 has this regression.

I can't attach a test case via bugs-by-mail, please contact me for a
complete test with the necessary fonts and screenshots with right and
wrong spacing.

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