--auto-hybrid-regex bad offset into UTF string

[InvisOn]

--auto-hybrid-regex should produce the same output as --pcre2 if one passes in a PCRE2 pattern. However, it throws an error on some files.

I've included the following examples and files.

• Offending pdf file to reproduce the rror can be downloaded here: https://onlinelibrary.wiley.com/doi/10.1111/j.1472-4642.2008.00521.x
• Another file which does not present this problem and shows identical output: https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02549.x

With --auto-hybrid-regex:

rga '(?=.*biotic interaction)(?=.*plant)' 'Diversity and Distributions - 2008 - Catford - Reducing redundancy in invasion ecology by integrating hypotheses into a.pdf' --auto-hybrid-regex

Faulty output:

Diversity and Distributions - 2008 - Catford - Reducing redundancy in invasion ecology by integrating hypotheses into a.pdf: preprocessor command failed: '"/home/aj/.cargo/bin/rga-preproc" "Diversity and Distributions - 2008 - Catford - Reducing redundancy in invasion ecology by integrating hypotheses into a.pdf"': PCRE2: error matching: bad offset into UTF string

With --pcre2:

rga '(?=.*biotic interaction)(?=.*plant)' 'Diversity and Distributions - 2008 - Catford - Reducing redundancy in invasion ecology by integrating hypotheses into a.pdf' --pcre2

Correct output:

Page 18: Vázquez, D.P. (2006) Biotic interactions and plant invasions.