The issues found fell into these categories, with the applied fixes:
- const was accidentally stripped.
Adjust code to not cast or cast with const.
- const/volatile missing from arguments, local variables.
Constify arguments or variables, adjust/delete casts. Small code
changes in a few places.
- const must be stripped because an API dependency requires it.
Strip `const` with `CURL_UNCONST()` macro to silence the warning out
of our control. These happen at API boundaries. Sometimes they depend
on dependency version, which this patch handles as necessary. Also
enable const support for the zlib API, using `ZLIB_CONST`. Supported
by zlib 1.2.5.2 and newer.
- const must be stripped because a curl API requires it.
Strip `const` with `CURL_UNCONST()` macro to silence the warning out
of our immediate control. For example we promise to send a non-const
argument to a callback, though the data is const internally.
- other cases where we may avoid const stripping by code changes.
Also silenced with `CURL_UNCONST()`.
- there are 3 places where `CURL_UNCONST()` is cast again to const.
To silence this type of warning:
```
lib/vquic/curl_osslq.c:1015:29: error: to be safe all intermediate
pointers in cast from 'unsigned char **' to 'const unsigned char **'
must be 'const' qualified [-Werror=cast-qual]
lib/cf-socket.c:734:32: error: to be safe all intermediate pointers in
cast from 'char **' to 'const char **' must be 'const' qualified
[-Werror=cast-qual]
```
There may be a better solution, but I couldn't find it.
These cases are handled in separate subcommits, but without further
markup.
If you see a `-Wcast-qual` warning in curl, we appreciate your report
about it.
Closes#16142
- Make curl_multi_waitfds consistent with the documentation.
Issue Addressed:
- The documentation of curl_multi_waitfds indicates that users should
be able to call curl_multi_waitfds with a NULL ufds. However, before
this change, the function would return CURLM_BAD_FUNCTION_ARGUMENT.
- Additionally, the documentation suggests that users can use this
function to determine the number of file descriptors (fds) needed.
However, the function would stop counting fds if the supplied fds
were exhausted.
Changes Made:
- NULL ufds Handling: curl_multi_waitfds can now accept a NULL ufds if
size is also zero.
- Counting File Descriptors: If curl_multi_waitfds is passed a NULL
ufds, or the size of ufds is insufficient, the output parameter
fd_count will return the number of fds needed. This value may be
higher than actually needed but never lower.
Testing:
- Test 2405 has been updated to cover the usage scenarios described
above.
Fixes https://github.com/curl/curl/issues/15146
Closes https://github.com/curl/curl/pull/15155
Before this patch, the result code was a mixture of `int` and
`CURLcode`.
Also adjust casts and fix a couple of minor issues found along the way.
Cherry-picked from #13489Closes#13600
