Sav variable display width becomes 0 if string variables longer than 255 characters

[ofajardo]

I am using readstat_variable_set_display_width to set the variable display width when writing a sav file. It is working, meaning when reading the written file I can get the display variable width with readstat_variable_get_display_width and it looks correct.

However if the dataset contains a value which is a string with 256 characters or more, writing it and reading again, then when using readstat_variable_get_display_width I get 0, interestingly not only for the variable containing the long string, but for any other variable in the dataset.

The long string itself is read correctly.

[evanmiller]

Thank you for the report. Please try 03ba85c

[ofajardo]

it works! thanks!

Just one more question: it seems that the max value is 255, if I enter something higher it goes back to 255. Is that intentional? (SPSS does accet widths larger than 255)

[evanmiller]

The display width is stored in two separate places. In the "legacy" location the width is limited to 255. In the new location there is no limit. I will need to tinker with it some more to make sure the proper location is used.

[evanmiller]

Can you provide a test case and ensure you are using the latest code? My tests pass using display widths of e.g. 1000.

[ofajardo]

hmm, attached the python script I am using, and the resulting file, setting it to 1000 and I recover 255 from readstat_variable_get_display_width (I am also printing the call to readstat_variable_get_display_width internally, not in the script, Im printing just below this line
https://github.com/Roche/pyreadstat/blob/dev/pyreadstat/_readstat_parser.pyx#L474)

PSPP in the other hand says it is correct (1000) ... so now I am confused

Archive.zip

[evanmiller]

Try this 3fe313f

It looks like the display record was not being read correctly with long strings. I didn't notice this before because the function's return value was never checked (and short strings were fine).

[ofajardo]

yes, that fully solves it!

thanks!