Problem:    Command line completion not fully tested.
Solution:   Add more test cases.  Make help sorting stable. (Dominique Pelle,
            closes vim/vim#5402)
https://github.com/vim/vim/commit/297610ba4b110c918ffe60c45eb4a1d6ea2daae5

Problem:    After ":cd" fails ":cd -" is incorrect.
Solution:   Set the previous directory only after successfully changing
            directory. (Richard Doty, closes vim/vim#9419, closes vim/vim#8983)
https://github.com/vim/vim/commit/3d0abad5bf4fe125e219f1b56c4e8200cb900e2a

Adjust the test's error message check due to missing patch

vim-patch:8.2.3973: tiny build fails

Problem:    Tiny build fails.
Solution:   Adjust #ifdefs
https://github.com/vim/vim/commit/0f7a5e758c5d8be2d8f1ab4a145d1636a36d18b2

vim-patch:8.2.3978: build error when using dynamycally loaded Python 3

Problem:    Build error when using dynamycally loaded Python 3.
Solution:   Adjust #ifdef.
https://github.com/vim/vim/commit/6b1a99dfe33cf5a1d7f82febd81face85ac1b8a6

vim-patch:8.2.4013: build failure without the spell feature

Problem:    Build failure without the spell feature.
Solution:   Adjust #ifdefs.
https://github.com/vim/vim/commit/e60b3c47d701e73ecbadb1b9a12bf82010cadae8

vim-patch:8.2.4032: ATTRIBUTE_NORETURN is not needed

Problem:    ATTRIBUTE_NORETURN is not needed.
Solution:   Use NORETURN(). (Ozaki Kiichi, closes vim/vim#9487)
https://github.com/vim/vim/commit/e12406526a24768e6121450112eb2f9f92445ac5

vim-patch:8.2.4048: gcc complains about use of "%p" in printf

Problem:    gcc complains about use of "%p" in printf.
Solution:   Add (void *) typecast. (Dominique Pellé, closes vim/vim#9494)
https://github.com/vim/vim/commit/c14f667626ba677a767d474324306e39096dc43e

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
https://github.com/vim/vim/commit/4c313b13fb7bfa694ec6d2a13175e8650c007b2a

The rest of this patch was ported in
https://github.com/neovim/neovim/commit/3137c7d63574a86ddc44f11c839e8e58c2994bf9

N/A patches for version.c:

vim-patch:8.1.2012: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make terminal functions usable as a method.  Fix term_getattr().
https://github.com/vim/vim/commit/7ee80f766130f22598c928415c92ec612a8f18cf

vim-patch:8.2.3576: some functions are not documented for use with a method

Problem:    Some functions are not documented for use with a method.
Solution:   Add examples.  Fix that sign_unplacelist() only takes one
            argument. (Sean Dewar, closes vim/vim#9081)
https://github.com/vim/vim/commit/a63780b9770699bf8fda93affeab2c728bc76912

Addressed in the port of v8.1.1995.

Problem:    getcwd() is unclear about how 'autochdir' is used.
Solution:   Update the help for getcwd().  Without any arguments always return
            the actual current directory. (closes vim/vim#9142)
https://github.com/vim/vim/commit/851c7a699ae00bdc14a4db874cf722b7b7393b53

Problem:    Problem with :cd when editing file in non-existent directory. (Yee
            Cheng Chin)
Solution:   Prepend the current directory to get the full path. (closes vim/vim#8903)
https://github.com/vim/vim/commit/c6376c798433bcb9ee38a8664299d11454546950

Problem:    when splitting a window localdir is copied but prevdir is not.
Solution:   Also copy prevdir. (closes vim/vim#6667)
https://github.com/vim/vim/commit/a9a47d157ab1946d1e286c9695bc68d71305af68

Problem:    Cannot go back to the previous local directory.
Solution:   Add "tcd -" and "lcd -". (Yegappan Lakshmanan, closes vim/vim#4362)
https://github.com/vim/vim/commit/002bc79991286934a9593b80635c27d4238cdfc4

Problem:    :pwd does not give a hint about the scope of the directory
Solution:   Make ":verbose pwd" show the scope. (Takuya Fujiwara, closes vim/vim#5469)
https://github.com/vim/vim/commit/950587242cad52d067a15f0f0c83528a28f75731

Problem:    cd() with NULL argument crashes.
Solution:   Check for NULL. (Ken Takata, closes vim/vim#5558)
https://github.com/vim/vim/commit/7cc96923c44bbcc541cbd211b6308d87a965f0c3