vim-patch:8.2.1289: crash when using a custom completion function (#13565)

Problem:    Crash when using a custom completion function.
Solution:   Initialize all of the expand_T. (closes vim/vim#6532)
https://github.com/vim/vim/commit/c841afff6a89592f23710c6da5b0fea89b240937

Cherry-pick CLEAR_POINTER macro from patch v8.2.0559.

N/A patches for version.c:

vim-patch:8.1.1295: when vimrun.exe does not exist external command may fail

Problem:    When vimrun.exe does not exist external command may fail.
Solution:   Use "cmd /c" twice to get the same behavior. (Ken Takata,
            closes vim/vim#4355)
https://github.com/vim/vim/commit/98ffe4c6d8bded840436cfec0f26dd9c9bce4939

vim-patch:8.2.2155: warning from Github actions for code analysis

Problem:    Warning from Github actions for code analysis.
Solution:   Remove the "git checkout HEAD^2" block.
https://github.com/vim/vim/commit/18f69229c581a0f738145cdec70df66723a518fc

vim-patch:8.2.2156: Github actions run on pusing a tag

Problem:    Github actions run on pusing a tag.
Solution:   Don't run CI on tag push. Omit coveralls on pull-request.
            (Ozaki Kiichi, closes vim/vim#7489)
https://github.com/vim/vim/commit/b5b77378bc35cb268c384e98c59f2bf8cb406270

vim-patch:8.2.2158: CI on cirrus times out, coveralls doesn't always run

Problem:    CI on cirrus times out, coveralls doesn't always run.
Solution:   Set timeout to 20 minutes. Adjust condition. (closes vim/vim#7493)
https://github.com/vim/vim/commit/6e562fcc07c71ad1437c89c3d3cc423efb691f0a

2 files changed, 4 insertions, 9 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index a0910f1394..129cb323ea 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4229,17 +4229,11 @@ ExpandOne (
  * Prepare an expand structure for use.
  */
 void ExpandInit(expand_T *xp)
+  FUNC_ATTR_NONNULL_ALL
 {
-  xp->xp_pattern = NULL;
-  xp->xp_pattern_len = 0;
+  CLEAR_POINTER(xp);
   xp->xp_backslash = XP_BS_NONE;
-#ifndef BACKSLASH_IN_FILENAME
-  xp->xp_shell = FALSE;
-#endif
   xp->xp_numfiles = -1;
-  xp->xp_files = NULL;
-  xp->xp_arg = NULL;
-  xp->xp_line = NULL;
 }
 
 /*
@@ -5399,7 +5393,7 @@ static void expand_shellcmd(char_u *filepat, int *num_file, char_u ***file,
 }
 
 /// Call "user_expand_func()" to invoke a user defined Vim script function and
-/// return the result (either a string or a List).
+/// return the result (either a string, a List or NULL).
 static void * call_user_expand_func(user_expand_func_T user_expand_func,
                                     expand_T *xp, int *num_file, char_u ***file)
   FUNC_ATTR_NONNULL_ALL
diff --git a/src/nvim/vim.h b/src/nvim/vim.h
index 900f2acd81..01f20cf29a 100644
--- a/src/nvim/vim.h
+++ b/src/nvim/vim.h
@@ -208,6 +208,7 @@ enum { FOLD_TEXT_LEN = 51 };  //!< buffer size for get_foldtext()
 // Size in bytes of the hash used in the undo file.
 #define UNDO_HASH_SIZE 32
 
+#define CLEAR_POINTER(ptr)  memset((ptr), 0, sizeof(*(ptr)))
 
 // defines to avoid typecasts from (char_u *) to (char *) and back
 // (vim_strchr() is now in strings.c)