Horizontal spacing regression in 1.50.3
The problem is very similar (if not identical) to issue #404. What basically happens is that some glyphs have extra horizontal space when full type hinting is used.
This was "miraculously" fixed somewhere between 1.44 and 1.50, and reappeared between 1.50.2 and 1.50.3. I tracked down the change to commit 22f8df57, and looking at the commit description, it makes sense.
If I understand correctly, that commit reverts a previous commit that breaks vertical spacing. It seems that both pango_hb_font_get_glyph_h_advance() and pango_hb_font_get_glyph_v_advance() are modified in a similar manner. Would it be possible or make any sense to keep only the horizontal spacing part of the original commit? I am not familiar with the pango code base, so I apologize in advance if this doesn't make any sense.