patch 9.2.0049: Vim9: typename() wrong for lists/dicts/tuples with shared references

Problem:  Vim9: typename() returns wrong type for lists/dicts/tuples
          with shared references (Mao-Yining).
Solution: Reset CopyID after processing the item so it can be
          re-inspected if encountered again via a different reference
          (Hirohito Higashi).

fixes:  #19490
closes: #19492

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_tuple.vim

@@ -2238,6 +2238,14 @@ func Test_tuple_typename()
   END
   call v9.CheckSourceDefAndScriptSuccess(lines)
 
+  " Shared (non-circular) references must not be treated as circular.
+  " repeat() makes all elements point to the same inner tuple object.
+  let lines =<< trim END
+    call assert_equal('tuple<tuple<number, number>, tuple<number, number>, tuple<number, number>>', ((1, 2),)->repeat(3)->typename())
+    call assert_equal('list<tuple<number, number>>', [(1, 2)]->repeat(3)->typename())
+  END
+  call v9.CheckSourceLegacyAndVim9Success(lines)
+
   " When a tuple item is used in a "for" loop, the type is tuple<any>
   let lines =<< trim END
     vim9script

src/testdir/test_vim9_builtin.vim

@@ -4983,6 +4983,22 @@ def Test_typename()
   endif
   var l: list<func(list<number>): any> = [function('min')]
   assert_equal('list<func(list<number>): any>', typename(l))
+
+  # Check that circular list/dict references don't cause infinite recursion.
+  # Use legacy script where lv_type is not set so the copyID mechanism is used.
+  v9.CheckSourceLegacySuccess([
+        'let circ_l = []',
+        'call add(circ_l, circ_l)',
+        "call assert_equal('list<list<any>>', typename(circ_l))",
+        'let circ_d = {}',
+        "let circ_d['self'] = circ_d",
+        "call assert_equal('dict<dict<any>>', typename(circ_d))",
+  ])
+
+  # Shared (non-circular) references must not be treated as circular.
+  # repeat() makes all elements point to the same inner list/dict object.
+  assert_equal('list<list<string>>', [[" "]]->repeat(3)->typename())
+  assert_equal('list<dict<number>>', [{'a': 1}]->repeat(3)->typename())
 enddef
 
 def Test_undofile()

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    49,
 /**/
     48,
 /**/

src/vim9type.c

@@ -612,6 +612,10 @@ list_typval2type(typval_T *tv, int copyID, garray_T *type_gap, int flags)
 	common_type(typval2type(&li->li_tv, copyID, type_gap, TVTT_DO_MEMBER),
 					member_type, &member_type, type_gap);
 
+    // Reset copyID so that a shared reference to this list (not a circular
+    // reference) can be processed again to get the correct type.
+    l->lv_copyID = 0;
+
     return get_list_type(member_type, type_gap);
 }
 
@@ -661,6 +665,9 @@ tuple_typval2type(typval_T *tv, int copyID, garray_T *type_gap, int flags)
 	if (ga_grow(&tuple_types_ga, 1) == FAIL)
 	{
 	    ga_clear(&tuple_types_ga);
+	    // Reset copyID so that a shared reference to this tuple can be
+	    // processed again.
+	    tuple->tv_copyID = 0;
 	    return NULL;
 	}
 	((type_T **)tuple_types_ga.ga_data)[tuple_types_ga.ga_len] = type;
@@ -670,6 +677,10 @@ tuple_typval2type(typval_T *tv, int copyID, garray_T *type_gap, int flags)
     type_T *tuple_type = get_tuple_type(&tuple_types_ga, type_gap);
     ga_clear(&tuple_types_ga);
 
+    // Reset copyID so that a shared reference to this tuple (not a circular
+    // reference) can be processed again to get the correct type.
+    tuple->tv_copyID = 0;
+
     return tuple_type;
 }
 
@@ -716,6 +727,10 @@ dict_typval2type(typval_T *tv, int copyID, garray_T *type_gap, int flags)
 	common_type(typval2type(value, copyID, type_gap, TVTT_DO_MEMBER),
 					member_type, &member_type, type_gap);
 
+    // Reset copyID so that a shared reference to this dict (not a circular
+    // reference) can be processed again to get the correct type.
+    d->dv_copyID = 0;
+
     return get_dict_type(member_type, type_gap);
 }