vim-patch:8.2.3378: MS-Windows: completing environment variables with % is wrong

Problem:    MS-Windows: completing environment variables with % is wrong.
Solution:   Only complete environment variables with $. (Albert Liu,
            closes vim/vim#8791)
6024c0427c

The change itself in set_one_cmd_context() is N/A (it was never included
in Neovim to begin with).

N/A patches for version.c:

vim-patch:8.2.3379: crash when using NULL job

Problem:    Crash when using NULL job.
Solution:   Copy static string into buffer. (issue vim/vim#8260)
271906bc06

src/nvim/ex_docmd.c

@@ -3229,7 +3229,7 @@ const char * set_one_cmd_context(expand_T *xp, const char *buff)
         }
       }
     }
-    // Check for user names
+    // Check for user names.
     if (*xp->xp_pattern == '~') {
       for (p = (const char *)xp->xp_pattern + 1; *p != NUL && *p != '/'; p++) {
       }