This issue is applicable to Adlam and N'Ko.

When text contains a punctuation mark such as an Arabic question mark, the glyph displayed should be that contained in the Adlam or N'Ko font, if it contains one.

The Gap:

At least one browser on desktop and mobile render the Arabic question mark (and perhaps other punctuation) using a fallback font despite the font containing the appropriate glyph.

Example in N'Ko:

This was tested with the Noto Sans NKo font. In Gecko and Blink the question mark falls back to a different font.

It may be related to a script itemization issue where Adlam or N'Ko is not properly recognized. A request was made to the Unicode Consortium to fix the Script Extensions table.

Other characters from the Arabic and Devanagari script blocks exhibit the same behaviour. For example, a danda used in Limbu, or a tatweel used in Syriac.

More:

• GitHub issue

Tests & results:

• Interactive test, If an N'Ko font contains an Arabic question mark, the glyph rendered should be from that font, and not fall back to an another font.
  

Action taken:

Gecko

Outcomes

The Unicode Consortium has fixed the script extensions table.

Gecko is implementing a fix.

Priority:

A question mark is visible, just not in the correct font. So marking as advanced.