Update comments for expand_wildcards functions.

Be more specific in the description of mch_expand_wildcards():
This function will never free memory pointed to by its arguments.
If OK is returned, *file will always point to allocated memory.
*num_file is set to the number of pointers in *file.
If FAIL is returned *file is set to NULL and *num_file to 0.

If gen_expand_wildcards() returns FAIL, no memory allocation in this
function needs to be undone.

If expand_wildcards() returns FAIL, no memory allocation in this
function needs to be undone.

Helped-by: Eliseo Martínez <eliseomarmol@gmail.com>
Helped-by: Michael Reed <m.reed@mykolab.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index d430509cfd..cd63b4fa90 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -3810,16 +3810,17 @@ void ExpandGeneric(
   reset_expand_highlight();
 }
 
-/*
- * Complete a shell command.
- */
-static void
-expand_shellcmd (
-    char_u *filepat,           /* pattern to match with command names */
-    int *num_file,          /* return: number of matches */
-    char_u ***file,            /* return: array with matches */
-    int flagsarg                   /* EW_ flags */
-)
+/// Complete a shell command.
+///
+/// @param      filepat  is a pattern to match with command names.
+/// @param[out] num_file is pointer to number of matches.
+/// @param[out] file     is pointer to array of pointers to matches.
+///                      *file will either be set to NULL or point to
+///                      allocated memory.
+/// @param      flagsarg is a combination of EW_* flags.
+static void expand_shellcmd(char_u *filepat, int *num_file, char_u ***file,
+                            int flagsarg)
+    FUNC_ATTR_NONNULL_ALL
 {
   char_u      *pat;
   int i;