strptime() on OS X and *BSDs (reputedly) does not set tm_wday and
tm_yday unless corresponding %U and %j format specifiers were used.
That can be... surprising when one parsed year, month, and day anyways.
Glibc's strptime() conveniently sets tm_wday and tm_yday in those cases,
but OS X's does not, ignoring them completely.
This commit makes jq compute those where possible, though the day of
week computation may be wrong for dates before 1900-03-01 or after
2099-12-31.
OS X (and *BSD) strptime() does not set tm_wday nor tm_yday unless
corresponding format options are used. That means we must call timegm()
to set them.
It needs to be possible to do something like
getpath($paths[]) += 1
meaning: increment all the paths in . that are listed in $paths[].
In order to do this getpath() needs to update the jq->path and
jq->value_at_path as necessary.
Configure should still allow use of prebuilt onigurumas (whether
system-installed or in a special prefix). If these are not found, and
configure was not called with `--without-oniguruma`, then use the vendored
oniguruma module. If configure was called with `--without-oniguruma`, then we
do not build regex functionality into jq.
strptime() is an XPG4v2 function, on OpenBSD the prototype
is not included in time.h unless visibility is set, it needs
either "#define _XOPEN_SOURCE_EXTENDED 1" or _XOPEN_SOURCE
>= 500. Without this the prototype isn't included and
strptime's returned pointer is truncated to an int, causing
SEGV on 64-bit arches when using it.
Thanks @sthen
Nicolas Williams