René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Type42 font embedding broken for fonts without glyph names","articleBody":"\u003c!--To help us understand and resolve your issue, please fill out the form to the best of your ability.--\u003e\r\n\u003c!--You can feel free to delete the sections that do not apply.--\u003e\r\n\r\n### Bug report\r\n\r\n**Bug summary**\r\n\r\nSetting `pdf.fonttype` or `ps.fonttype` to 42 and using a font with no glyph names (i.e. for which FT_HAS_GLYPH_NAMES returns 0) results in non-displayed text.\r\n\r\n**Code for reproduction**\r\n\r\n\u003c!--A minimum code snippet required to reproduce the bug.\r\nPlease make sure to minimize the number of dependencies required, and provide\r\nany necessary plotted data.\r\nAvoid using threads, as Matplotlib is (explicitly) not thread-safe.--\u003e\r\n\r\nArial is a prominent font with no glyph names (so it's not a completely obscure edge case...).\r\n\r\n```python\r\nfrom pathlib import Path\r\nrcParams.update({\"pdf.fonttype\": 42, \"ps.fonttype\": 42}\r\nfigtext(.5, .5, \"ab\", font=\"arial\")\r\nsavefig(\"/tmp/test.pdf\")\r\nsavefig(\"/tmp/test.ps\")\r\n```\r\n\r\n**Actual outcome**\r\n\r\nFiles are displayed as empty.\r\n\r\n**Expected outcome**\r\n\r\nText is shown.\r\n\r\n---\r\n\r\nAgain https://github.com/matplotlib/matplotlib/pull/18143 may be relevant here: perhaps fontTools can generate the glyph names table if needed?\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system: fedora\r\n  * Matplotlib version: master\r\n  * Python version: 38\r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\n\r\n","author":{"url":"https://github.com/anntzer","@type":"Person","name":"anntzer"},"datePublished":"2020-08-20T14:37:43.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/18307/matplotlib/issues/18307"}