The following fixes have been backported to this maintenance release. All users of the library are encouraged to update.
adfece0 array: fix search for empty arrays
5a9d850 odb: only provide the empty tree
ed5299a odb: actually insert the empty blob in tests
886bd6a mwindow: init mwindow files in git_libgit2_init
edf420f cmake: add curl library path
e499b13 git_checkout_tree options fix
12b73ff transports: http: reset `connected` flag when re-connecting transport
0dea429 ignore: allow unignoring basenames in subdirectories
8f342c6 stransport: do not use `git_stream_free` on uninitialized stransport
9aee7bc stransport: make internal functions static
b64722f SecureTransport: handle NULL trust on success
1fafead sysdir: use the standard `init` pattern
85adddd refspec: do not set empty rhs for fetch refspecs
d711165 repository: don't cast to `int` for no reason
9894c7d remote: Handle missing config values when deleting a remote
49188d2 blame: do not decrement commit refcount in make_origin
1edbfa1 Fixed bug while parsing INT64_MIN
a200dc9 Fix repository discovery with ceiling_dirs at current directory
c7a0336 cmake: do not use -fPIC for MSYS2
cc43d18 README: update "Getting Help" section
ce124fc README: improve contributing paragraph
90ec160 README: disambiguate what to distribute source of
bb582f0 threads: add platform-independent thread initialization function
5d03db8 win32: rename pthread.{c,h} to thread.{c,h}
961bdbd threads: remove now-useless typedefs
2aa5c6f threads: remove unused function pthread_num_processors_np
68343f2 threads: split up OS-dependent rwlock code
fabd477 threads: split up OS-dependent thread-condition code
1b82531 threads: remove unused function pthread_cond_broadcast
40b243b threads: split up OS-dependent mutex code
fc2b97d threads: split up OS-dependent thread code
286e7db fix error message SHA truncation in git_odb__error_notfound()
4c06f3e HTTP authentication scheme name is case insensitive.
ac44d35 checkout: use empty baseline when no index
a574d84 documentation: improve docs for `checkout_head`
27008e8 fetch: Fixed spurious update callback for existing tags.
d1fb89d global: clean up crt only after freeing tls data
6e0d473 tests: fix memory leaks in checkout::typechange
246d25b index: fix NULL pointer access in index_remove_entry
1a70960 transports: smart: fix potential invalid memory dereferences
11408f0 index_read_index: invalidate new paths in tree cache
8be4968 test: ensure we can round-trip a written tree
80745b1 index_read_index: set flags for path_len correctly
e755f79 index_read_index: differentiate on mode
e6a0a85 index_read_index: reset error correctly
6c133a7 round-trip trees through index_read_index
feea284 win32: clean up unused warnings in DllMain
efadf28 filebuf: fix uninitialized warning
bcef008 cleanup: unused warning
68227c4 Update CMakeLists.txt
85ef6ec Ignore submodules when checking for merge conflicts in the workdir.
70681ff checkout: handle dirty submodules correctly
26917fd test: Fix stat() test to mask out unwanted bits
488937c CMakeLists: Add libnetwork for Haiku
78b5702 Fix comment for GIT_FILEMODE_LINK
849a1a4 Fix unused variable 'message' warning
cf0396a delta-apply: fix sign extension
1fb8a95 odb_loose: fix undefined behavior when computing size
f627e19 checkout: set ignorecase=0 when config lookup fails
66633e8 odb: avoid inflating the full delta to read the header
fc2ef51 index: fix memory leak on error case
1aacaa3 cmake: include threading libraries in pkg-config
b726c53 Fix return value of openssl_read (infinite loop)
16541b8 tag: ignore extra header fields