When multiple -arch flags are used, the compiler invokes itself once for
each architecture. Apparently, input on stdin is consumed by the
compilation of the first arch and is no longer available to the
compilation of the second arch, which results in a build failure and the
potentially incorrect determination that a feature is not available. So
write the feature detection source to a file instead of using stdin.
fix#1379
decodecorpus was generating one extraneous byte when `nbSeq==0`.
This is disallowed by the specification.
The reference decoder was just skipping the extraneous byte.
It is now stricter, and flag such situation as an error.
gcc-8 on Linux doesn't like usage of strncat :
`warning: ‘strncat’ output truncated before terminating nul copying as many bytes from a string as its length`.
Not sure what was wrong, it might be a false positive,
but the logic is simple enough to replaced by a simple `memcpy()`,
thus avoiding the shenanigans of null-terminated strings.
following #1356,
only enable backtrace compilation on linux+glibc.
Also, disable backtrace by default from "release" compilation,
so that less platforms get impacted by the new requirements.
Can be manually enabled/disabled using BACKTRACE=1/0.
and slightly refactored affected function.
Honestly, the formula calculating variance should get a second reviewing round,
it's not clear if it's correct.
some non-trivial changes to platform.h and util.h,
initially related to compilation for Haiku,
but I used this opportunity to make them cleaner
and add some documentation.
Noticed several tests that could be improved
(too harsh conditions, useless exception, etc.)
but I did not dare modifying too many tests just before release.
note : for some reason,
scan-build version on my laptop found problems within fastcover.c
that scan-build on travisCI does not flag.
They are, as usual, false positive :
the analyzer does not understand that a table (`offset`) is correctly filled before usage.
