Format CIF, too long comments result in error "Stream has unknown format"

[electronum]

I have the impression the error appears when reaching a certain number of characters in comments, it seems it does not matetr where and how the comments are distributed. I counted: the errors appears starting with 3993 characters (including braces), look at the last line, the capital 'D' is the only character "too much".

Is it a bug or is there some limitation I am not aware of?

Tested in KLayout Viewer 0.25.9 and 0.26.8

Steps to reproduce

• Open file in KLayout -> error
• Edit the file in text editor: remove one comment character (for example the capital 'D' in the last comment)
• Reload file in KLayout -> OK

Minimum Working Example

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(Lorem ipsum D)

DS 100 100 1;
L SomeLayer;
B 100 200 0 0;
DF;

E

[klayoutmatthias]

That's true.

Here is the reason and the motivation:

dbCIF.cc, 71++:
      //  analyze the first 4000 characters - this is within the initial block read
      //  by the stream and won't trigger a reset of the stream which is not available
      //  on some sources.
      std::string head = s.read_all (4000);

Matthias