This is a workaround for an unsolved travis issue that is causing CI
instances to sporadically fail due to 'unable to connect' issues during
apt stage.

Ref: https://github.com/travis-ci/travis-ci/issues/8507
Ref: https://github.com/travis-ci/travis-ci/issues/9112#issuecomment-376305909

Update clang to version 3.9 and GCC to version 6.

Closes https://github.com/curl/curl/pull/2345

... to verify it builds and works fine.

Ref: https://curl.haxx.se/mail/lib-2017-09/0031.html

Closes #1872

.. since now mac osx image expects pip2 or pip3, and doesn't know pip:

0.01s$ pip install --user cpp-coveralls
/Users/travis/.travis/job_stages: line 57: pip: command not found

Ref: https://github.com/travis-ci/travis-ci/issues/8829

Closes https://github.com/curl/curl/pull/2133

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

Uses a separate build without --enable-debug and no valgrind.

The debug option causes far too many warnings in boringssl's headers
(C++ comments, trailing commas etc).  Valgrind triggers some false
positive errors in thread-local data used by boringssl.

Closes #2118

We don't expect any steps to fail in travis. Exit the script if they do.

Closes #1966

Use the external curl-fuzzer repository for fuzzing.

Closes #1923

- openssl is already installed and causes warnings when trying to
  install again

- libidn isn't used these days, and homebrew doesn't seem to have a
  libidn2 package to replace with easily

Closes #1895

Closes https://github.com/curl/curl/pull/1687

Closes #1868

Automake gets confused if you want to use C++ static libraries with C
code - basically we need to involve the clang++ linker. The easiest way
of achieving this is to rename the C code as C++ code. This gets us a
bit further along the path and ought to be compatible with Google's
version of clang.

- Start with the basic code from the ossfuzz project.
- Rewrite fuzz corpora to be binary files full of Type-Length-Value
  data, and write a glue layer in the fuzzing function to convert
  corpora into CURL options.
- Have supporting functions to generate corpora from existing tests
- Integrate with Makefile.am

Closes #1790

closes #1747

to make sure they keep building warning-free

Closes #1777

Could've prevented #1755

Help-by: Jay Satiro
Closes #1753

This makes the builds more reproducible as travis is currently rolling
out trusty as default dist [1]. Specifically, this avoids coverage
check failures when trusty is used as seen in [2] until we figure out
what's wrong.

[1] https://blog.travis-ci.com/2017-07-11-trusty-as-default-linux-is-coming
[2] https://github.com/curl/curl/pull/1692

Closes https://github.com/curl/curl/pull/1725

(to make the full line appear nicer on travis web UI)

Closes #1706

Install libidn2 to increase test coverage (IDN tests)

Closes https://github.com/curl/curl/pull/1673

... to get warnings also on Linux/GCC and OSX/clang.

Closes https://github.com/curl/curl/pull/1666

Install libssh2 to increase test coverage (SFTP, SCP)

Closes #1653

I added a selection of torture and event tests that run "fast enough"

Closes #1642

... to better detect and fault on compiler warnings/errors

Closes #1637

- switch debug and release configurations so that we get an optimized
  build with GCC 4.3+ as required by typecheck-gcc
- enable warnings-as-errors for release builds
  (which have warnings disabled)

Closes https://github.com/curl/curl/pull/1595

typecheck-gcc and other things require optimized builds

Closes #1544

Closes #1534