[Bug]: MinFontSize may not be correctly initialised (e.g. streamlit)

[lfoppiano]

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Hi all,
we're building a streamlit component for visualising PDF documents, and we are facing an issue with the text layer, in particular, in certain cases, when the streamlit application contains several tabs (each tab is a iframe, running pdf.js, rouhgly) on Chrome it might happens that the minimum font size is not detected correctly making the textlayer not to be rendered anymore.

We've investigated the issue and, looking at the code

pdf.js/src/display/text_layer.js

Line 488 in 5b29e93

this.#minFontSize = div.getBoundingClientRect().height;

we were wondering whether is acceptable to return 0 as minimum font size.

Here a project that reproduce the issue.

Web browser and its version

Chrome

Operating system and its version

N/A

PDF.js version

4.3.136

Is the bug present in the latest PDF.js version?

Yes

Is a browser extension

No

Steps to reproduce the problem

1. pull and run https://github.com/lfoppiano/streamlit-test
2. Enter a directory path in the visualised textbox (they will be loaded in separate tabs, so a directory with 5 scientific articles should be enough)
3. a set of tabs will be opened, if you click on the second or third , the text won't be selecteable, sometimes an exception is also thrown

What is the expected behavior?

The expected behaviour is to have selecteable text in all pdf in all tabs

What went wrong?

It seems an issue with the min font size. See here.

Link to a viewer

No response

Additional context

No response