In case a read callback returns a status (pause, abort, eof,
error) instead of a byte count, drain the bytes read so far but
remember this status for further processing.
Takes care of not losing data when pausing, and properly resume a
paused mime structure when requested.
New tests 670-673 check unpausing cases, with easy or multi
interface and mime or form api.

Fixes #4813
Reported-by: MrdUkk on github

Due to the merge/revert cycle

This reverts commit 87869e38d7afdec3ef1bb4965711458b088e254f.

Fixes #5014
Closes #5015
Reopens #4833

In case a read callback returns a status (pause, abort, eof,
error) instead of a byte count, drain the bytes read so far but
remember this status for further processing.
Takes care of not losing data when pausing, and properly resume a
paused mime structure when requested.
New tests 670-673 check unpausing cases, with easy or multi
interface and mime or form api.

Fixes #4813
Reported-by: MrdUkk on github
Closes #4833

Codacy/CppCheck warns about this. Consistently use parentheses as we
already do in some places to silence the warning.

Closes https://github.com/curl/curl/pull/3866

This enables level 4 instead of the default level 3, which of the
currently used comments only allows /* FALLTHROUGH */ to silence the
warning.

Closes https://github.com/curl/curl/pull/2747

On Windows, casting between unrelated function types is fine and
sometimes even necessary, so just use an intermediate cast to
(void (*) (void)) to silence the warning as described in [0].

[0] https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html

Closes https://github.com/curl/curl/pull/2860

Its usage was removed in
84ad1fd3047815f9c6e78728bb351b828eac10b1.

Closes #2852

- Get rid of variable that was generating false positive warning
(unitialized)

- Fix issues in tests

- Reduce scope of several variables all over

etc

Closes #2631