path.c: Fix memory leak in expand_wildcards().

A file that matches with one of the patterns in 'wildignore' is ignored
when using expand_wildcards(). After removing ignored files, the array
of (file name) matches can be empty. But an empty array is never freed.

2 files changed, 18 insertions, 8 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 03116d454f..a9d371d0eb 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4112,10 +4112,11 @@ void globpath(char_u *path, char_u *file, garray_T *ga, int expand_options)
       STRCAT(buf, file);  // NOLINT
 
       char_u **p;
-      int num_p;
-      if (ExpandFromContext(&xpc, buf, &num_p, &p,
-              WILD_SILENT|expand_options) != FAIL && num_p > 0) {
-        ExpandEscape(&xpc, buf, num_p, p, WILD_SILENT|expand_options);
+      int num_p = 0;
+      (void)ExpandFromContext(&xpc, buf, &num_p, &p,
+                              WILD_SILENT | expand_options);
+      if (num_p > 0) {
+        ExpandEscape(&xpc, buf, num_p, p, WILD_SILENT | expand_options);
 
         // Concatenate new results to previous ones.
         ga_grow(ga, num_p);
diff --git a/src/nvim/path.c b/src/nvim/path.c
index a3b5bb7490..1a1f15e8f3 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -1843,7 +1843,11 @@ char_u *path_shorten_fname(char_u *full_path, char_u *dir_name)
 /// @param[out]  file      Array of resulting files.
 /// @param[in]   flags     Flags passed to expand_wildcards().
 ///
-/// @return OK or FAIL.
+/// @returns               OK when *file is set to allocated array of matches
+///                        and *num_file(can be zero) to the number of matches.
+///                        If FAIL is returned, *num_file and *file are either
+///                        unchanged or *num_file is set to 0 and *file is set
+///                        to NULL or points to "".
 int expand_wildcards_eval(char_u **pat, int *num_file, char_u ***file,
                           int flags)
 {
@@ -1882,9 +1886,8 @@ int expand_wildcards_eval(char_u **pat, int *num_file, char_u ***file,
 /// @param[out] file     is pointer to array of pointers to matched file names.
 /// @param      flags    is a combination of EW_* flags.
 ///
-/// @returns             OK when some files were found. *num_file is set to the
-///                      number of matches, *file to the allocated array of
-///                      matches.
+/// @returns             OK when *file is set to allocated array of matches
+///                      and *num_file (can be zero) to the number of matches.
 ///                      If FAIL is returned, *num_file and *file are either
 ///                      unchanged or *num_file is set to 0 and *file is set to
 ///                      NULL or points to "".
@@ -1944,6 +1947,12 @@ int expand_wildcards(int num_pat, char_u **pat, int *num_file, char_u ***file,
     }
   }
 
+  // Free empty array of matches
+  if (*num_file == 0) {
+    xfree(*file);
+    *file = NULL;
+  }
+
   return retval;
 }