vim-patch:7.4.1567

Problem:    Crash in assert_fails().
Solution:   Check for NULL. (Dominique Pelle)  Add a test.

1abb502635

src/nvim/eval.c

@@ -7688,7 +7688,8 @@ static void f_assert_fails(typval_T *argvars, typval_T *rettv)
     char_u buf[NUMBUFLEN];
     char *error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
 
-    if (strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL) {
+    if (error == NULL
+        || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL) {
       prepare_assert_error(&ga);
       fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
                         &vimvars[VV_ERRMSG].vv_tv);

src/nvim/version.c

@@ -119,7 +119,7 @@ static int included_patches[] = {
   1570,
   1569,
   1568,
-  // 1567,
+  1567,
   // 1566 NA
   // 1565,
   // 1564,

test/functional/legacy/assert_spec.lua

@@ -142,4 +142,22 @@ describe('assert function:', function()
       })
     end)
   end)
+
+  -- assert_fails({cmd}, [, {error}])
+  describe('assert_fails', function()
+    it('should change v:errors when error does not match v:errmsg', function()
+      execute([[call assert_fails('xxx', {})]])
+      expected_errors({"Expected {} but got 'E731: using Dictionary as a String'"})
+    end)
+
+    it('should not change v:errors when cmd errors', function()
+      call('assert_fails', 'NonexistentCmd')
+      expected_empty()
+    end)
+
+    it('should change v:errors when cmd succeeds', function()
+      call('assert_fails', 'call empty("")')
+      expected_errors({'command did not fail: call empty("")'})
+    end)
+  end)
 end)