doc2ipf and int_error

[Petr M. <mi...@ph...>]

Compiling of doc2ipf is broken:

$ make doc2ipf
doc2ipf.o: In function `process_line':
/home/mikulik/work/Software/gnuplot/gnuplot/docs/doc2ipf.c:406: undefined 
reference to `int_error'

It's strange because process_line() does not call directly int_error().
Any idea how to fix this?
(doc2ipf is required to generate the hypertext documentation for OS/2.)

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PM