The infinity symbol on page 3 of the file of
PDFBOX-1770 is not rendered. I am attaching a "bad" and a "good" rendering. The "good" rendering was faked by removing the line
in Type1Glyph2D. This helps keeping a "C121" in a map instead of being replaced with a "y". The font involved is the "KIJFMP+AdvTex2" font.