Release 1.21.2
downloader: Compare HTTP header names case-insensitively
metadata_downloader: Don't use error messages as format strings
Fix swapped function arguments
repomd: Fix a warning message and a memory leak
downloader: Accept file descriptor 0 in lr_download()
Don't pass negative values to ctype functions
checksum: Fix a memory leak and an out-of-bounds read
Fix leaks of zchunk contexts on error paths
package_downloader: Restore the SIGINT handler on all return paths
mirrorlist: Close the duplicated descriptor if fdopen() fails
repoutil_yum: Use S_ISDIR() to check for a directory
util: Handle partial writes in lr_copy_content()
xmlparser: Check the parser context before using it
downloader: hold transfer state per connection, not per target
tests: Run the repo_zck test suite
handle: Validate the new value of LRO_MAXMIRRORTRIES
downloader: don't rescan every target when nothing can be started