Thunderbird bz 579023 still not fixed even though there is an upstream fix available

Chris Tyler chris at
Tue Apr 27 22:46:43 UTC 2010

On Tue, 2010-04-27 at 23:55 +0200, Kevin Kofler wrote:
> You mean "compliance" with Mozilla's own "standards" such as APNG which 
> require a bundled hacked version of a system library to support?

Kevin, you keep bringing up APNG, so let me address that one. I know the
story because the Mozilla implementation was originally written by a
former student, Andrew Smith. The decision to back PNG and fork libpng
was not made lightly -- it's a significant maintenance burden for

APNG was created to fill a void -- there was a need for a modern
animated format with two qualities: it needed to be lightweight and
backward-compatible (degrade gracefully). After nearly a year of
discussion and consultation, the PNG group decided not to back it;
Mozilla gave it further thought and decided they needed it. It has since
been implemented by other browsers (such as Opera) and used in other
applications (such as WorldDMB, see ESTI TS 101 499 V2.2.1).

The alternative, MNG, is a heavy spec that offers no graceful
degradation for older browsers. It's been around for years, but is
almost never used. If it was a lighter spec, surely we'd be using it for
animated cursors and throbbers by now.


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