From aa6821ce14464a9cd67c10033c85052c10c06c84 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Sun, 6 Aug 2023 18:40:54 -0500
Subject: [PATCH] Enable shell command recursion.

---
 main.c            |  4 ++--
 toys.h            |  1 +
 toys/pending/sh.c | 19 ++++++++++++-------
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/main.c b/main.c
index b4971bcd..6fc27099 100644
--- a/main.c
+++ b/main.c
@@ -207,7 +207,7 @@ void toy_init(struct toy_list *which, char *argv[])
 
 // Run an internal toybox command.
 // Only returns if it can't run command internally, otherwise xexit() when done.
-static void toy_exec_which(struct toy_list *which, char *argv[])
+void toy_exec_which(struct toy_list *which, char *argv[])
 {
   // Return if we can't find it (which includes no multiplexer case),
   if (!which || (which->flags&TOYFLAG_NOFORK)) return;
@@ -219,7 +219,7 @@ static void toy_exec_which(struct toy_list *which, char *argv[])
   // Signed typecast so stack growth direction is irrelevant: we're measuring
   // the distance between two pointers on the same stack, hence the labs().
   if (!CFG_TOYBOX_NORECURSE && toys.stacktop)
-    if (labs((long)toys.stacktop-(long)&which)>6000) return;
+    if (labs((long)toys.stacktop-(long)&which)>24000) return;
 
   // Return if we need to re-exec to acquire root via suid bit.
   if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return;
diff --git a/toys.h b/toys.h
index ebe0a321..49b02ffb 100644
--- a/toys.h
+++ b/toys.h
@@ -92,6 +92,7 @@ void show_help(FILE *out, int full);
 void check_help(char **arg);
 void toy_singleinit(struct toy_list *which, char *argv[]);
 void toy_init(struct toy_list *which, char *argv[]);
+void toy_exec_which(struct toy_list *which, char *argv[]);
 void toy_exec(char *argv[]);
 
 // Array of available commands
diff --git a/toys/pending/sh.c b/toys/pending/sh.c
index 139c394d..fc9edcff 100644
--- a/toys/pending/sh.c
+++ b/toys/pending/sh.c
@@ -2704,16 +2704,18 @@ notfd:
 // Call binary, or run script via xexec("sh --")
 static void sh_exec(char **argv)
 {
-  char *pp = getvar("PATH" ? : _PATH_DEFPATH), *cc = TT.isexec ? : *argv, *ss,
+  char *pp = getvar("PATH" ? : _PATH_DEFPATH), *ss = TT.isexec ? : *argv,
     **sss = 0, **oldenv = environ, **argv2;
-  struct string_list *sl;
+  struct string_list *sl = 0;
+  struct toy_list *tl = 0;
 
   if (getpid() != TT.pid) signal(SIGINT, SIG_DFL); // TODO: restore all?
   errno = ENOENT;
-  if (strchr(ss = cc, '/')) {
+  if (strchr(ss, '/')) {
     if (access(ss, X_OK)) ss = 0;
-  } else for (sl = find_in_path(pp, cc); sl || (ss = 0); free(llist_pop(&sl)))
-    if (!access(ss = sl->str, X_OK)) break;
+  } else if (CFG_TOYBOX_NORECURSE || !toys.stacktop || !(tl = toy_find(ss)))
+    for (sl = find_in_path(pp, ss); sl || (ss = 0); free(llist_pop(&sl)))
+      if (!access(ss = sl->str, X_OK)) break;
 
   if (ss) {
     struct sh_vars **vv = visible_vars();
@@ -2730,13 +2732,16 @@ static void sh_exec(char **argv)
     }
     aa.v[aa.c] = 0;
     if (!sss) {
-      arg_add(&aa, 0);
+      if (aa.c<uu) aa.v[++aa.c] = 0;
+      else arg_add(&aa, 0);
       sss = aa.v+aa.c-1;
     }
     *sss = xmprintf("_=%s", ss);
 
-    // exec or source
+    // Run builtin, exec command, or call shell script without #!
+    toy_exec_which(tl, argv);
     execve(ss, argv, environ);
+    // shell script without #!
     if (errno == ENOEXEC) {
       for (argc = 0; argv[argc]; argc++);
       argv2 = xmalloc((argc+3)*sizeof(char *));
-- 
2.39.2