eval/typval: Add tv_list_equal() tests, compare NULL lists equal

src/nvim/eval/typval.c

@@ -623,13 +623,12 @@ bool tv_list_equal(list_T *const l1, list_T *const l2, const bool ic,
                    const bool recursive)
   FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  if (l1 == NULL || l2 == NULL) {
-    // FIXME? compare empty list with NULL list equal
-    return false;
-  }
   if (l1 == l2) {
     return true;
   }
+  if (l1 == NULL || l2 == NULL) {
+    return false;
+  }
   if (tv_list_len(l1) != tv_list_len(l2)) {
     return false;
   }

test/functional/eval/null_spec.lua

@@ -57,12 +57,6 @@ describe('NULL', function()
     null_list_expr_test('does not crash extend()', 'extend(L, [1])', 0, 0)
     -- FIXME extend() should not return 0 at all
     null_list_expr_test('does not crash extend() (second position)', 'extend([1], L)', 0, 0)
-    -- FIXME Should return 1
-    null_list_expr_test('is equal to itself', 'L == L', 0, 0)
-    -- FIXME Should return 0
-    null_list_expr_test('is not not equal to itself', 'L != L', 0, 1)
-    -- FIXME Should return 1
-    null_list_expr_test('counts correctly', 'count([L], L)', 0, 0)
     -- FIXME should be accepted by inputlist()
     null_list_expr_test('is accepted as an empty list by inputlist()',
                         '[feedkeys("\\n"), inputlist(L)]', 'E686: Argument of inputlist() must be a List', {0, 0})
@@ -133,5 +127,8 @@ describe('NULL', function()
     null_list_expr_test('can be added to itself', '(L + L) is L', 0, 1)
     null_list_expr_test('can be added to non-empty list', '([1] + L)', 0, {1})
     null_list_expr_test('can be added to non-empty list (reversed)', '(L + [1])', 0, {1})
+    null_list_expr_test('is equal to itself', 'L == L', 0, 1)
+    null_list_expr_test('is not not equal to itself', 'L != L', 0, 0)
+    null_list_expr_test('counts correctly', 'count([L], L)', 0, 1)
   end)
 end)

test/unit/eval/typval_spec.lua

@@ -1031,7 +1031,6 @@ describe('typval.c', function()
         eq(empty_list, typvalt2lua(rettv4))
       end)
     end)
-  end)
     describe('join()', function()
       local function list_join(l, sep, ret)
         local ga = ga_alloc()
@@ -1040,7 +1039,7 @@ describe('typval.c', function()
         else return ffi.string(ga.ga_data)
         end
       end
-    it('works', function()
+      itp('works', function()
         local l
         l = list('boo', 'far')
         eq('boo far', list_join(l, ' '))
@@ -1066,4 +1065,74 @@ describe('typval.c', function()
         lib.tv_list_free(l, true)
       end)
     end)
+    describe('equal()', function()
+      itp('compares empty and NULL lists correctly', function()
+        local l = list()
+        local l2 = list()
+
+        -- NULL lists are not equal to empty lists
+        eq(false, lib.tv_list_equal(l, nil, true, false))
+        eq(false, lib.tv_list_equal(nil, l, false, false))
+        eq(false, lib.tv_list_equal(nil, l, false, true))
+        eq(false, lib.tv_list_equal(l, nil, true, true))
+
+        -- Yet NULL lists are equal themselves
+        eq(true, lib.tv_list_equal(nil, nil, true, false))
+        eq(true, lib.tv_list_equal(nil, nil, false, false))
+        eq(true, lib.tv_list_equal(nil, nil, false, true))
+        eq(true, lib.tv_list_equal(nil, nil, true, true))
+
+        -- As well as empty lists
+        eq(true, lib.tv_list_equal(l, l, true, false))
+        eq(true, lib.tv_list_equal(l, l2, false, false))
+        eq(true, lib.tv_list_equal(l2, l, false, true))
+        eq(true, lib.tv_list_equal(l2, l2, true, true))
+      end)
+      -- Must not use recursive=true argument in the following tests because it
+      -- indicates that tv_equal_recurse_limit and recursive_cnt were set which
+      -- is essential. This argument will be set when comparing inner lists.
+      itp('compares lists correctly when case is not ignored', function()
+        local l1 = list('abc', {1, 2, 'Abc'}, 'def')
+        local l2 = list('abc', {1, 2, 'Abc'})
+        local l3 = list('abc', {1, 2, 'Abc'}, 'Def')
+        local l4 = list('abc', {1, 2, 'Abc', 4}, 'def')
+        local l5 = list('Abc', {1, 2, 'Abc'}, 'def')
+        local l6 = list('abc', {1, 2, 'Abc'}, 'def')
+        local l7 = list('abc', {1, 2, 'abc'}, 'def')
+        local l8 = list('abc', nil, 'def')
+        local l9 = list('abc', {1, 2, nil}, 'def')
+
+        eq(true, lib.tv_list_equal(l1, l1, false, false))
+        eq(false, lib.tv_list_equal(l1, l2, false, false))
+        eq(false, lib.tv_list_equal(l1, l3, false, false))
+        eq(false, lib.tv_list_equal(l1, l4, false, false))
+        eq(false, lib.tv_list_equal(l1, l5, false, false))
+        eq(true, lib.tv_list_equal(l1, l6, false, false))
+        eq(false, lib.tv_list_equal(l1, l7, false, false))
+        eq(false, lib.tv_list_equal(l1, l8, false, false))
+        eq(false, lib.tv_list_equal(l1, l9, false, false))
+      end)
+      itp('compares lists correctly when case is ignored', function()
+        local l1 = list('abc', {1, 2, 'Abc'}, 'def')
+        local l2 = list('abc', {1, 2, 'Abc'})
+        local l3 = list('abc', {1, 2, 'Abc'}, 'Def')
+        local l4 = list('abc', {1, 2, 'Abc', 4}, 'def')
+        local l5 = list('Abc', {1, 2, 'Abc'}, 'def')
+        local l6 = list('abc', {1, 2, 'Abc'}, 'def')
+        local l7 = list('abc', {1, 2, 'abc'}, 'def')
+        local l8 = list('abc', nil, 'def')
+        local l9 = list('abc', {1, 2, nil}, 'def')
+
+        eq(true, lib.tv_list_equal(l1, l1, true, false))
+        eq(false, lib.tv_list_equal(l1, l2, true, false))
+        eq(true, lib.tv_list_equal(l1, l3, true, false))
+        eq(false, lib.tv_list_equal(l1, l4, true, false))
+        eq(true, lib.tv_list_equal(l1, l5, true, false))
+        eq(true, lib.tv_list_equal(l1, l6, true, false))
+        eq(true, lib.tv_list_equal(l1, l7, true, false))
+        eq(false, lib.tv_list_equal(l1, l8, true, false))
+        eq(false, lib.tv_list_equal(l1, l9, true, false))
+      end)
+    end)
+  end)
 end)