kc3-lang/kc3

diff --git a/ikc3/.ikc3_history b/ikc3/.ikc3_history
index 3ab3c7a..fbf887c 100644
--- a/ikc3/.ikc3_history
+++ b/ikc3/.ikc3_history
@@ -1,5 +1,3 @@
-if true do if true do %KC3.Operator{sym: :-, symbol_value: 3} else fn (x) do x * x end end end
-type(0)
 type(-1)
 def operator_muul = %KC3.Operator{sym: :****, symbol_value: fn (a, b) { a * a + b * b }
 }
@@ -97,3 +95,5 @@ List.sort_by([1, 2, 3, 4], fn (a, b) { a > b })
 List.sort_by([%{title: "Abc", time: %Time{}}, %{title: "Cde", time: %Time{tv_sec: 1000}}], fn (a, b) { a.time < b.time })
 List.sort_by([%{title: "Abc", time: %Time{}}, %{title: "Cde", time: %Time{tv_sec: 1000}}], fn (a, b) { a.time > b.time })
 File.list_files_recursive("../www/pages")
+t = Thread.new(fn () { puts("ok") })
+Thread.delete(t)
diff --git a/libkc3/kc3.c b/libkc3/kc3.c
index f5f7fea..f0c807d 100644
--- a/libkc3/kc3.c
+++ b/libkc3/kc3.c
@@ -713,25 +713,25 @@ void kc3_system_pipe_exec (s32 pipe_w, char **argv,
 s_tag * kc3_thread_delete (u_ptr_w *thread, s_tag *dest)
 {
   pthread_t t;
-  s_tag *tmp;
-  t = thread->p;
-  if (pthread_join(t, (void **) &tmp)) {
+  s_tag *tag;
+  t = (pthread_t) thread->p;
+  if (pthread_join(t, (void **) &tag)) {
     err_puts("kc3_thread_delete: pthread_join");
     assert(! "kc3_thread_delete: pthread_join");
     return NULL;
   }
-  if (tmp->type != TAG_TUPLE ||
-      tmp->data.tuple.count != 2) {
+  if (tag->type != TAG_TUPLE ||
+      tag->data.tuple.count != 3) {
     err_puts("kc3_thread_delete: invalid value");
     assert(! "kc3_thread_delete: invalid value");
-    tag_delete(tmp);
+    tag_delete(tag);
     return NULL;
   }
-  if (! tag_init_copy(dest, tmp->data.tuple.tag)) {
-    tag_delete(tmp);
+  if (! tag_init_copy(dest, tag->data.tuple.tag)) {
+    tag_delete(tag);
     return NULL;
   }
-  tag_delete(tmp);
+  tag_delete(tag);
   return dest;
 }
 
@@ -745,7 +745,7 @@ u_ptr_w * kc3_thread_new (u_ptr_w *dest, p_callable *start)
     return NULL;
   }
   tag->data.tuple.tag[2].type = TAG_PTR;
-  if (! (tag->data.tuple.tag[2].data.ptr.p = env_new_copy(g_kc3_env))) {
+  if (! (tag->data.tuple.tag[2].data.ptr.p = g_kc3_env)) {
     tag_delete(tag);
     return NULL;
   }
@@ -756,7 +756,6 @@ u_ptr_w * kc3_thread_new (u_ptr_w *dest, p_callable *start)
     tag_delete(tag);
     return NULL;
   }
-  tag_delete(tag);
   return dest;
 }
 
@@ -765,15 +764,32 @@ void * kc3_thread_start (void *arg)
   s_tag *tag;
   s_callable *start;
   tag = arg;
-  if (tag->type != TAG_TUPLE ||
-      tag->data.tuple.count != 3 ||
-      tag->data.tuple.tag[1].type != TAG_CALLABLE ||
-      tag->data.tuple.tag[2].type != TAG_PTR) {
-    err_puts("kc3_thread_start: invalid argument");
-    assert(! "kc3_thread_start: invalid argument");
+  if (tag->type != TAG_TUPLE) {
+    err_puts("kc3_thread_start: invalid argument: not a tuple");
+    assert(! "kc3_thread_start: invalid argument: not a tuple");
+    return NULL;
+  }
+  if (tag->data.tuple.count != 3) {
+    err_puts("kc3_thread_start: invalid argument:"
+             " tuple arity mismatch");
+    assert(!("kc3_thread_start: invalid argument:"
+             " tuple arity mismatch"));
+    return NULL;
+  }
+  if (tag->data.tuple.tag[1].type != TAG_CALLABLE) {
+    err_puts("kc3_thread_start: invalid argument:"
+             " not a Callable (Fn or Cfn)");
+    assert(!("kc3_thread_start: invalid argument:"
+             " not a Callable (Fn or Cfn)"));
+    return NULL;
+  }
+  if (tag->data.tuple.tag[2].type != TAG_PTR) {
+    err_puts("kc3_thread_start: invalid argument: not a Ptr");
+    assert(! "kc3_thread_start: invalid argument: not a Ptr");
     return NULL;
   }
   start = tag->data.tuple.tag[1].data.callable;
+  g_kc3_env = env_new_copy((s_env *) tag->data.tuple.tag[2].data.ptr.p);
   if (! eval_callable_call(start, NULL, tag->data.tuple.tag))
     return NULL;
   return tag;