RunGeometry bounds fix

[ickshonpe]

Objective

We sum GlyphRun::offset and LineMetrics::inline_min_coord when calculating the run geometry bounding boxes during text layout. But this is incorrect because GlyphRun::offset is set equal to offset + self.line.data.metrics.inline_min_coord + self.line.data.metrics.offset, so inline_min_coord is added twice.

We don't see any errors in layout because BreakerState::set_line_x isn't used anywhere atm, so the value of inline_min_coord is always zero, but it's still wrong.

Solution

Don't add inline_min_coord to the run bounds.

[urben1680]

We don't see any errors in layout because

... we lack tests? 😄 Can you add one for this?

[ickshonpe]

We don't see any errors in layout because

... we lack tests? 😄 Can you add one for this?

Not sure that it's possible to create a meaningful test for this (without larger changes to the text systems), update_text_layout_info calls break_all_lines which erases any offsets set with set_line_x. So even though the calculations are wrong, the output values are always correct.