4 files changed, 30 insertions, 10 deletions

diff --git a/coreutils/test.c b/coreutils/test.c
index ad777953f..6085d6663 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -638,7 +638,7 @@ static int binop(void)
 static int is_a_group_member(gid_t gid)
 {
         /* Short-circuit if possible, maybe saving a call to getgroups(). */
-        if (gid == getgid() || gid == getegid())
+        if (gid == get_cached_egid(&groupinfo->egid))
                 return 1;
 
         return is_in_supplementary_groups(groupinfo, gid);
@@ -656,15 +656,16 @@ static int test_st_mode(struct stat *st, int mode)
 
 //TODO  if (mode == X_OK) {
 //              /* Do we already know with no extra syscalls? */
-//              if (!S_ISREG(st->st_mode))
-//                      return 0; /* not a regular file */
+//              //if (!S_ISREG(st->st_mode))
+//              //      return 0; /* not a regular file */
+//              // ^^^ bash does not check this
 //              if ((st->st_mode & ANY_IX) == 0)
 //                      return 0; /* no one can execute */
 //              if ((st->st_mode & ANY_IX) == ANY_IX)
 //                      return 1; /* anyone can execute */
 //      }
 
-        euid = geteuid();
+        euid = get_cached_euid(&groupinfo->euid);
         if (euid == 0) {
                 /* Root can read or write any file. */
                 if (mode != X_OK)
@@ -1019,6 +1020,8 @@ int test_main(int argc, char **argv)
         struct cached_groupinfo info;
         int r;
 
+        info.euid = -1;
+        info.egid = -1;
         info.ngroups = 0;
         info.supplementary_array = NULL;
         r = test_main2(&info, argc, argv);
diff --git a/include/libbb.h b/include/libbb.h
index 8748464ed..f5f8e1635 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1206,11 +1206,13 @@ gid_t *bb_getgroups(int *ngroups, gid_t *group_array) FAST_FUNC;
  * getgroups() is cached in supplementary_array[], to make successive calls faster.
  */
 struct cached_groupinfo {
-        //TODO? gid_t egid;
+        uid_t euid;
+        gid_t egid;
         int ngroups;
         gid_t *supplementary_array;
 };
-//TODO? int FAST_FUNC get_cached_egid(gid_t *egid);
+uid_t FAST_FUNC get_cached_euid(uid_t *euid);
+gid_t FAST_FUNC get_cached_egid(gid_t *egid);
 int FAST_FUNC is_in_supplementary_groups(struct cached_groupinfo *groupinfo, gid_t gid);
 
 #if ENABLE_FEATURE_UTMP
diff --git a/libbb/bb_getgroups.c b/libbb/bb_getgroups.c
index d9bbe95c3..31cff2b41 100644
--- a/libbb/bb_getgroups.c
+++ b/libbb/bb_getgroups.c
@@ -46,6 +46,20 @@ gid_t* FAST_FUNC bb_getgroups(int *ngroups, gid_t *group_array)
         return group_array;
 }
 
+uid_t FAST_FUNC get_cached_euid(uid_t *euid)
+{
+        if (*euid == (uid_t)-1)
+                *euid = geteuid();
+        return *euid;
+}
+
+gid_t FAST_FUNC get_cached_egid(gid_t *egid)
+{
+        if (*egid == (gid_t)-1)
+                *egid = getegid();
+        return *egid;
+}
+
 /* 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)
 {
diff --git a/shell/ash.c b/shell/ash.c
index a6bb9894c..9173b8608 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -536,6 +536,8 @@ extern struct globals_misc *BB_GLOBAL_CONST ash_ptr_to_globals_misc;
         curdir = nullstr; \
         physdir = nullstr; \
         trap_ptr = trap; \
+        groupinfo.euid = -1; \
+        groupinfo.egid = -1; \
 } while (0)
 
 
@@ -2319,7 +2321,7 @@ initvar(void)
 #if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT
         vps1.var_text = "PS1=\\w \\$ ";
 #else
-        if (!geteuid())
+        if (!get_cached_euid(&groupinfo.euid));
                 vps1.var_text = "PS1=# ";
 #endif
         vp = varinit;
@@ -13809,14 +13811,13 @@ static int test_exec(/*const char *fullname,*/ struct stat *statb)
 
         /* Executability depends on our euid/egid/supplementary groups */
         stmode = S_IXOTH;
-        euid = geteuid();
-//TODO: cache euid?
+        euid = get_cached_euid(&groupinfo.euid);
         if (euid == 0)
                 /* for root user, any X bit is good enough */
                 stmode = ANY_IX;
         else if (statb->st_uid == euid)
                 stmode = S_IXUSR;
-        else if (statb->st_gid == getegid())
+        else if (statb->st_gid == get_cached_egid(&groupinfo.egid))
                 stmode = S_IXGRP;
         else if (is_in_supplementary_groups(&groupinfo, statb->st_gid))
                 stmode = S_IXGRP;