Data is either copied from the input file or decompressed from the input
file depending on state->how. If state->how is LOOK, then a gzip header is
looked for (and skipped if found) to discern whether to copy or decompress.
- Returns -1 on error, otherwise 0. gz_make() will leave state->have as COPY
+ Returns -1 on error, otherwise 0. gz_make() will leave state->how as COPY
or GZIP unless the end of the input file has been reached and all data has
been processed. */
local int gz_make(state)