[text-area] Max rows doesn't work if `line-height: normal` is used for the input field

[jouni]

Description

If the line-height for the internal input-field part is normal, the maxRows property doesn't have any effect.

Expected outcome

The input field height is constrained to the specified maxRows.

Minimal reproducible example

<style>
  vaadin-text-area::part(input-field) {
    line-height: normal;
  }
</style>
<vaadin-text-area max-rows="2" value="Value value value value value value value value value value value value value"></vaadin-text-area>

Steps to reproduce

Environment

Browsers

No response

[jouni]

The issue is that browsers report the string value 'normal' for getComputedStyle(...).lineHeight, instead of the effective pixel value.

The workaround/fix is likely to detect when it returns 'normal', then explicitly set the line-height to 1.2, which is approximately the default in most desktop browsers, and then get the new computed style value.