Created attachment 133909 [details]
A test DOCX with text run font size 20 pt

The attached file is a sanitized and minimized real-world document.
It has a single text run with text size set to 20 pt. Currently it opens in LO with text size of 10 pt, i.e. half of defined size.

The size is given using this markup:
> <w:sz w:val="20pt" />

This is illegal in first OOXML schema edition (i.e. 2007), but legal in later editions.

The type of the w:sz element is w:ST_HpsMeasure, which in later editions of standard (e.g. ECMA-376 5th ed. Part 1, 17.18.42) is defined as

> This simple type specifies that its contents contain either:
> * A positive whole number, whose contents consist of a measurement in half-points (equivalent to
> 1/144th of an inch), or
> * A positive decimal number immediately followed by a unit identifier.
...
> This simple type is a union of the following types:
> * The ST_PositiveUniversalMeasure simple type (§22.9.2.12).
> * The ST_UnsignedDecimalNumber simple type (§22.9.2.16).

We currently ignore the units specifications, and simply convert the integer part as it's half-pt measurement.