This fixes missing-variable-declarations warnings when building with
clang.

This fixes the following clang warnings:

http2.c:184:27: error: no previous extern declaration for non-static
variable 'Curl_handler_http2' [-Werror,-Wmissing-variable-declarations]
http2.c:204:27: error: no previous extern declaration for non-static
variable 'Curl_handler_http2_ssl'
[-Werror,-Wmissing-variable-declarations]

It's dangerous to continue to run the test when a memory alloc fails.

clang complains:

curl_rtmp.c:61:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmp' [-Werror,-Wmissing-variable-declarations]
curl_rtmp.c:81:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmpt' [-Werror,-Wmissing-variable-declarations]
curl_rtmp.c:101:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmpe' [-Werror,-Wmissing-variable-declarations]
curl_rtmp.c:121:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmpte' [-Werror,-Wmissing-variable-declarations]
curl_rtmp.c:141:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmps' [-Werror,-Wmissing-variable-declarations]
curl_rtmp.c:161:27: error: no previous extern declaration for non-static variable 'Curl_handler_rtmpts' [-Werror,-Wmissing-variable-declarations]

Fix this by including the header file.

Missed in commit 55c3c02e

Commit 80a87e8a broke 'make dist' as it can't handle installing from
absolute target names. Rearranged the dependencies so the absolute name
is used for building but the relative name is use for distributing.

This fixes the following clang warnings:
macro is not used [-Wunused-macros]
will never be executed [-Wunreachable-code]

Closes https://github.com/curl/curl/pull/1448

get_protocol_family() is not defined static even though there is a
static local forward declaration. Let's simply make the definition match
it's declaration.

Bug: https://curl.haxx.se/mail/lib-2017-04/0127.html

Uploads data to an FTP site, directly from memory.

Closes #1451

The module contains a more comprehensive set of trust information than
supported by nss-pem, because libnssckbi.so also includes information
about distrusted certificates.

Reviewed-by: Kai Engert
Closes #1414

No change of behavior is intended by this commit.

It could prevent nss-pem from being unloaded later on.

Bug: https://bugzilla.redhat.com/1444860

Info values starting with CURLINFO_SOCKET expect a curl_socket_t, not a
curl_slist argument.

This fixes the following GCC warning when building the examples with
--enable-optimize:

../../include/curl/typecheck-gcc.h:126:42: warning: call to
‘_curl_easy_getinfo_err_curl_slist’ declared with attribute warning:
curl_easy_getinfo expects a pointer to 'struct curl_slist *' for this
info [enabled by default]
sendrecv.c:90:11: note: in expansion of macro ‘curl_easy_getinfo’
res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);

Closes https://github.com/curl/curl/pull/1447

Test command 'time curl http://localhost/80GB -so /dev/null' on a Debian
Linux.

Before (middle performing run out 9):

 real    0m28.078s
 user    0m11.240s
 sys     0m12.876s

After (middle performing run out 9)

 real    0m26.356s (93.9%)
 user    0m5.324s  (47.4%)
 sys     0m8.368s  (65.0%)

Also, doing SFTP over a 200 millsecond latency link is now about 6 times
faster.

Closes #1446

The data->req.uploadbuf struct member served no good purpose, instead we
use ->state.uploadbuffer directly. It makes it clearer in the code which
buffer that's being used.

Removed the 'SingleRequest *' argument from the readwrite_upload() proto
as it can be derived from the Curl_easy struct. Also made the code in
the readwrite_upload() function use the 'k->' shortcut to all references
to struct fields in 'data->req', which previously was made with a mix of
both.

- Change prepends to appends because user's LDFLAGS and CPPFLAGS should
  always come first so they're searched before ours.

Bug: https://github.com/curl/curl/issues/1420
Reported-by: Helmut K. C. Tessarek

Follow-up to 11903732, which fixed the
warning in the HAVE_GETIFADDRS block, but not in the
HAVE_IOCTL_SIOCGIFADDR block.

$< is only allowed in implicit rules in some non-GNU makes (e.g. BSD,
AIX) so avoid use elsewhere by referencing the dependent curl.1 file
directly instead. This is somewhat tricky because the file is supplied
in the packaged tar ball (but not in git) but must still be able to be
rebuilt when its dependencies change. The right thing must happen in
both tar ball and git source trees, as well as in both in-tree and
out-of-tree builds.

This commit fixes compilation failure caused by
cbae73e1.

-Og, introduced in GCC 4.8, optimizes for debugging experience.
-Ofast, introduced in GCC 4.7, builds on -O3 and enables further
optimizations breaking strict standards compliance.
When specified in CFLAGS, these were always overridden by -O0 or -O2.
Fix this by adding them to flags_opt_all.

Ref: https://gcc.gnu.org/onlinedocs/gcc-4.8.0/gcc/Optimize-Options.html
Ref: https://github.com/curl/curl/pull/1404#issuecomment-296401570
Closes https://github.com/curl/curl/pull/1440

The check for if -ldl is needed to build with (a statically built)
openssl was broken. This repairs the check, and adds a check for
-lpthread as well since OpenSSL 1.1.0+ does in fact require -lpthread so
only adding -ldl for a static openssl build is no longer enough.

Reported-by: Jay Satiro
Ref: #1426
Closes #1427

Pointed-it-by: Kevin Ji
URL: https://github.com/curl/curl/commit/cbae73e1dd95946597ea74ccb580c30f78e3fa73#commitcomment-21872622

- Track when the cached encrypted data contains only a partial record
  that can't be decrypted without more data (SEC_E_INCOMPLETE_MESSAGE).

- Change Curl_schannel_data_pending to return false in such a case.

Other SSL libraries have pending data functions that behave similarly.

Ref: https://github.com/curl/curl/pull/1387

Closes https://github.com/curl/curl/pull/1392

`if(nfds || extra_nfds) {` is followed by `malloc(nfds * ...)`.

If `extra_fs` could be non-zero when `nfds` was zero, then we have
`malloc(0)` which is allowed to return `NULL`. But, malloc returning
NULL can be confusing. In this code, the next line would treat the NULL
as an allocation failure.

It turns out, if `nfds` is zero then `extra_nfds` must also be zero.
The final value of `nfds` includes `extra_nfds`.  So the test for
`extra_nfds` is redundant.  It can only confuse the reader.

Closes #1439

With -Og, GCC complains:

easy.c:628:7: error: ‘mcode’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

../lib/strcase.h:35:29: error: ‘tok_buf’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
vauth/digest.c:208:9: note: ‘tok_buf’ was declared here

../lib/strcase.h:35:29: error: ‘tok_buf’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
vauth/digest.c:566:15: note: ‘tok_buf’ was declared here

Fix this by initializing the variables.

This reduces the binary size and fixes a compile warning.

The 'list element' struct now has to be within the data that is being
added to the list. Removes 16.6% (tiny) mallocs from a simple HTTP
transfer. (96 => 80)

Also removed return codes since the llist functions can't fail now.

Test 1300 updated accordingly.

Closes #1435

All the callbacks passed to curl_easy_setopt are defined as function
pointers. The possibility to pass both functions and function pointers
was handled for the callbacks that typecheck-gcc.h defined as
compatible, but not for the public callback types themselves.

This makes all compatible callback types defined in typecheck-gcc.h
function pointers too and checks all functions uniformly with
_curl_callback_compatible, which handles both functions and function
pointers.

A symptom of the problem was a warning in tool_operate.c with
--disable-libcurl-option and without --enable-debug as that file
passes the callback functions to curl_easy_setopt directly.

Fixes https://github.com/curl/curl/issues/1403
Closes https://github.com/curl/curl/pull/1404