2 files changed, 10 insertions, 0 deletions

diff --git a/include/libbb.h b/include/libbb.h
index ff4a67481..11d52c08c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1273,7 +1273,11 @@ struct cached_groupinfo {
 };
 uid_t FAST_FUNC get_cached_euid(uid_t *euid);
 gid_t FAST_FUNC get_cached_egid(gid_t *egid);
+#if !ENABLE_PLATFORM_MINGW32
 int FAST_FUNC is_in_supplementary_groups(struct cached_groupinfo *groupinfo, gid_t gid);
+#else
+# define is_in_supplementary_groups(g, i) (FALSE)
+#endif
 
 #if ENABLE_FEATURE_UTMP
 void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname);
diff --git a/libbb/bb_getgroups.c b/libbb/bb_getgroups.c
index 31cff2b41..c255d4e4c 100644
--- a/libbb/bb_getgroups.c
+++ b/libbb/bb_getgroups.c
@@ -60,6 +60,11 @@ gid_t FAST_FUNC get_cached_egid(gid_t *egid)
         return *egid;
 }
 
+#if !ENABLE_PLATFORM_MINGW32
+// Both current callers of is_in_supplementary_groups() check the gid
+// first.  Our implementation of getgroups() provides no additional
+// information so there's no reason to call it.
+
 /* Return non-zero if GID is in our supplementary group list. */
 int FAST_FUNC is_in_supplementary_groups(struct cached_groupinfo *groupinfo, gid_t gid)
 {
@@ -79,3 +84,4 @@ int FAST_FUNC is_in_supplementary_groups(struct cached_groupinfo *groupinfo, gid
 
         return 0;
 }
+#endif