woff2_decompress fails with “implausible compression ratio”

[Lorp]

I get the following error when I attempt woff2_decompress on a woff2 font that I have just compressed using woff2_compress:

Implausible compression ratio 770.0

Admittedly the source TTF contains 65535 glyphs, almost all of which are duplicates. It is a test font, but I still expect to be able to decompress it.

[anthrotype]

interesting. Can fonttools decompress the font? Just curious...

[rsheeter]

This is a safeguard against fonts crafted to achieve exactly this type of memory explosion in the browser.
For local testing you can set what's allowed @

woff2/src/woff2_dec.cc

Line 67 in 3060d8b

const float kMaxPlausibleCompressionRatio = 100.0;

Browsers using the reference implementation will ofc reject such a font. I think this is working as intended unless evidence of realistic fonts with this kind of compression ratio emerge.