PDF Text missing (masked out) on pdf internal import (for a Inkscape-made file)
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#### Summary:
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Internally-imported text is completely missing. (I do not think it is the same as [3125](https://gitlab.com/inkscape/inbox/-/issues/3125) or [593](https://gitlab.com/inkscape/inkscape/-/issues/593), where the issue is missing characters.)
#### Steps to reproduce:
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Import [tmp_tldp.pdf](/uploads/1c65db375947804d903622c4e3b8ed19/tmp_tldp.pdf).
#### What happened?
The text was not imported.
#### What should have happened?
The text should have been imported.
Sample attachments:
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#### Version info
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```
Inkscape 1.1.1 (3bf5ae0d25, 2021-09-20)
GLib version: 2.70.0
GTK version: 3.24.30
glibmm version: 2.66.1
gtkmm version: 3.24.5
libxml2 version: 2.9.12
libxslt version: 1.1.34
Cairo version: 1.17.4
Pango version: 1.48.10
HarfBuzz version: 2.9.1
Poppler version: 21.08.0
OS version: Windows 10 1909
```
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issue