patch 8.2.3191: Vim9: not enough code is tested

Problem:    Vim9: not enough code is tested.
Solution:   Use CheckLegacyAndVim9Success() in more places.  Fix uncovered
            problems.

src/testdir/test_listdict.vim

@@ -1,5 +1,7 @@
 " Tests for the List and Dict types
 
+source vim9.vim
+
 func TearDown()
   " Run garbage collection after every test
   call test_garbagecollect_now()
@@ -44,66 +46,87 @@ endfunc
 
 " List identity
 func Test_list_identity()
-  let l = [1, 'as''d', [1, 2, function("strlen")], {'a': 1},]
+  let lines =<< trim END
-  let ll = l
+      VAR l = [1, 'as''d', [1, 2, function("strlen")], {'a': 1},]
-  let lx = copy(l)
+      VAR ll = l
+      VAR lx = copy(l)
       call assert_true(l == ll)
       call assert_false(l isnot ll)
       call assert_true(l is ll)
       call assert_true(l == lx)
       call assert_false(l is lx)
       call assert_true(l isnot lx)
+  END
+  call CheckLegacyAndVim9Success(lines)
 endfunc
 
 " removing items with :unlet
 func Test_list_unlet()
-  let l = [1, 'as''d', [1, 2, function("strlen")], {'a': 1},]
+  let lines =<< trim END
+      VAR l = [1, 'as''d', [1, 2, function("strlen")], {'a': 1},]
       unlet l[2]
       call assert_equal([1, 'as''d', {'a': 1}], l)
-  let l = range(8)
+      LET l = range(8)
       unlet l[: 3]
       unlet l[1 :]
       call assert_equal([4], l)
 
-  " removing items out of range: silently skip items that don't exist
+      #" removing items out of range: silently skip items that don't exist
-  let l = [0, 1, 2, 3]
+      LET l = [0, 1, 2, 3]
-  call assert_fails('unlet l[2:1]', 'E684:')
+      unlet l[2 : 2]
+      call assert_equal([0, 1, 3], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[2 : 3]
+      call assert_equal([0, 1], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[2 : 4]
+      call assert_equal([0, 1], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[2 : 5]
+      call assert_equal([0, 1], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[-2 : 2]
+      call assert_equal([0, 1, 3], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[-3 : 2]
+      call assert_equal([0, 3], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[-4 : 2]
+      call assert_equal([3], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[-5 : 2]
+      call assert_equal([3], l)
+      LET l = [0, 1, 2, 3]
+      unlet l[-6 : 2]
+      call assert_equal([3], l)
+  END
+  call CheckLegacyAndVim9Success(lines)
+
   let l = [0, 1, 2, 3]
   unlet l[2:2]
   call assert_equal([0, 1, 3], l)
   let l = [0, 1, 2, 3]
   unlet l[2:3]
   call assert_equal([0, 1], l)
+
   let l = [0, 1, 2, 3]
-  unlet l[2:4]
+  call assert_fails('unlet l[2:1]', 'E684:')
-  call assert_equal([0, 1], l)
-  let l = [0, 1, 2, 3]
-  unlet l[2:5]
-  call assert_equal([0, 1], l)
   let l = [0, 1, 2, 3]
   call assert_fails('unlet l[-1:2]', 'E684:')
-  let l = [0, 1, 2, 3]
-  unlet l[-2:2]
-  call assert_equal([0, 1, 3], l)
-  let l = [0, 1, 2, 3]
-  unlet l[-3:2]
-  call assert_equal([0, 3], l)
-  let l = [0, 1, 2, 3]
-  unlet l[-4:2]
-  call assert_equal([3], l)
-  let l = [0, 1, 2, 3]
-  unlet l[-5:2]
-  call assert_equal([3], l)
-  let l = [0, 1, 2, 3]
-  unlet l[-6:2]
-  call assert_equal([3], l)
 endfunc
 
 " assignment to a list
 func Test_list_assign()
-  let l = [0, 1, 2, 3]
+  let lines =<< trim END
-  let [va, vb] = l[2:3]
+      VAR l = [0, 1, 2, 3]
+      VAR va = 0
+      VAR vb = 0
+      LET [va, vb] = l[2 : 3]
       call assert_equal([2, 3], [va, vb])
+  END
+  call CheckLegacyAndVim9Success(lines)
+
+  let l = [0, 1, 2, 3]
   call assert_fails('let [va, vb] = l', 'E687:')
   call assert_fails('let [va, vb] = l[1:1]', 'E688:')
 endfunc
@@ -119,31 +142,34 @@ endfunc
 
 " Test removing items in list
 func Test_list_func_remove()
-  " Test removing 1 element
+  let lines =<< trim END
-  let l = [1, 2, 3, 4]
+      #" Test removing 1 element
+      VAR l = [1, 2, 3, 4]
       call assert_equal(1, remove(l, 0))
       call assert_equal([2, 3, 4], l)
 
-  let l = [1, 2, 3, 4]
+      LET l = [1, 2, 3, 4]
       call assert_equal(2, remove(l, 1))
       call assert_equal([1, 3, 4], l)
 
-  let l = [1, 2, 3, 4]
+      LET l = [1, 2, 3, 4]
       call assert_equal(4, remove(l, -1))
       call assert_equal([1, 2, 3], l)
 
-  " Test removing range of element(s)
+      #" Test removing range of element(s)
-  let l = [1, 2, 3, 4]
+      LET l = [1, 2, 3, 4]
       call assert_equal([3], remove(l, 2, 2))
       call assert_equal([1, 2, 4], l)
 
-  let l = [1, 2, 3, 4]
+      LET l = [1, 2, 3, 4]
       call assert_equal([2, 3], remove(l, 1, 2))
       call assert_equal([1, 4], l)
 
-  let l = [1, 2, 3, 4]
+      LET l = [1, 2, 3, 4]
       call assert_equal([2, 3], remove(l, -3, -2))
       call assert_equal([1, 4], l)
+  END
+  call CheckLegacyAndVim9Success(lines)
 
   " Test invalid cases
   let l = [1, 2, 3, 4]
@@ -156,7 +182,8 @@ endfunc
 
 " List add() function
 func Test_list_add()
-  let l = []
+  let lines =<< trim END
+      VAR l = []
       call add(l, 1)
       call add(l, [2, 3])
       call add(l, [])
@@ -165,6 +192,10 @@ func Test_list_add()
       call add(l, {})
       call add(l, test_null_dict())
       call assert_equal([1, [2, 3], [], [], {'k': 3}, {}, {}], l)
+  END
+  call CheckLegacyAndVim9Success(lines)
+
+  " weird legacy behavior
   call assert_equal(1, add(test_null_list(), 4))
 endfunc
 
@@ -172,11 +203,21 @@ endfunc
 
 func Test_dict()
   " Creating Dictionary directly with different types
-  let d = {001: 'asd', 'b': [1, 2, function('strlen')], -1: {'a': 1},}
+  let lines =<< trim END
+      VAR d = {'1': 'asd', 'b': [1, 2, function('strlen')], '-1': {'a': 1}, }
       call assert_equal("{'1': 'asd', 'b': [1, 2, function('strlen')], '-1': {'a': 1}}", string(d))
       call assert_equal('asd', d.1)
       call assert_equal(['-1', '1', 'b'], sort(keys(d)))
       call assert_equal(['asd', [1, 2, function('strlen')], {'a': 1}], values(d))
+      call extend(d, {3: 33, 1: 99})
+      call extend(d, {'b': 'bbb', 'c': 'ccc'}, "keep")
+      call assert_equal({'c': 'ccc', '1': 99, 'b': [1, 2, function('strlen')], '3': 33, '-1': {'a': 1}}, d)
+  END
+  call CheckLegacyAndVim9Success(lines)
+
+  let d = {001: 'asd', 'b': [1, 2, function('strlen')], -1: {'a': 1},}
+  call assert_equal("{'1': 'asd', 'b': [1, 2, function('strlen')], '-1': {'a': 1}}", string(d))
+
   let v = []
   for [key, val] in items(d)
     call extend(v, [key, val])
@@ -185,11 +226,7 @@ func Test_dict()
   call assert_equal(['1','asd','b',[1, 2, function('strlen')],'-1',{'a': 1}], v)
 
   call extend(d, {3: 33, 1: 99})
-  call extend(d, {'b':'bbb', 'c':'ccc'}, "keep")
   call assert_fails("call extend(d, {3:333,4:444}, 'error')", 'E737:')
-  call assert_equal({'c': 'ccc', '1': 99, 'b': [1, 2, function('strlen')], '3': 33, '-1': {'a': 1}}, d)
-  call filter(d, 'v:key =~ ''[ac391]''')
-  call assert_equal({'c': 'ccc', '1': 99, '3': 33, '-1': {'a': 1}}, d)
 
   " duplicate key
   call assert_fails("let d = {'k' : 10, 'k' : 20}", 'E721:')

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3191,
 /**/
     3190,
 /**/

src/vim9compile.c

@@ -6599,7 +6599,7 @@ compile_assign_unlet(
 		return FAIL;
 	    }
 	    type = ((type_T **)stack->ga_data)[stack->ga_len - 1];
-	    if ((dest_type != VAR_BLOB || type != &t_special)
+	    if ((dest_type != VAR_BLOB && type != &t_special)
 		    && need_type(type, &t_number,
 					    -1, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;

src/vim9execute.c

@@ -2679,7 +2679,8 @@ exec_instructions(ectx_T *ectx)
 			// indexes must be a number
 			SOURCING_LNUM = iptr->isn_lnum;
 			if (check_for_number(tv_idx1) == FAIL
-				|| check_for_number(tv_idx2) == FAIL)
+				|| (tv_idx2->v_type != VAR_SPECIAL
+					 && check_for_number(tv_idx2) == FAIL))
 			{
 			    status = FAIL;
 			}
@@ -2687,14 +2688,32 @@ exec_instructions(ectx_T *ectx)
 			{
 			    list_T	*l = tv_dest->vval.v_list;
 			    long	n1 = (long)tv_idx1->vval.v_number;
-			    long	n2 = (long)tv_idx2->vval.v_number;
+			    long	n2 = tv_idx2->v_type == VAR_SPECIAL
+					    ? 0 : (long)tv_idx2->vval.v_number;
 			    listitem_T	*li;
 
 			    li = list_find_index(l, &n1);
-			    if (li == NULL
+			    if (li == NULL)
-				     || list_unlet_range(l, li, NULL, n1,
-							    TRUE, n2) == FAIL)
 				status = FAIL;
+			    else
+			    {
+				if (n1 < 0)
+				    n1 = list_idx_of_item(l, li);
+				if (n2 < 0)
+				{
+				    listitem_T *li2 = list_find(l, n2);
+
+				    if (li2 == NULL)
+					status = FAIL;
+				    else
+					n2 = list_idx_of_item(l, li2);
+				}
+				if (status != FAIL
+					&& list_unlet_range(l, li, NULL, n1,
+					    tv_idx2->v_type != VAR_SPECIAL, n2)
+								       == FAIL)
+				    status = FAIL;
+			    }
 			}
 		    }
 		    else