[njs] Fixed equality operator with "null" value as right operand.

[Valentin Bartenev]

details:   http://hg.nginx.org/njs/rev/abec5f8d55a1
branches:  
changeset: 644:abec5f8d55a1
user:      Valentin Bartenev <vbart at nginx.com>
date:      Fri Nov 09 18:05:39 2018 +0300
description:
Fixed equality operator with "null" value as right operand.

diffstat:

 njs/njs_vm.c             |  9 +++++++--
 njs/test/njs_unit_test.c |  3 +++
 2 files changed, 10 insertions(+), 2 deletions(-)

diffs (33 lines):

diff -r c5a3ac902bc2 -r abec5f8d55a1 njs/njs_vm.c
--- a/njs/njs_vm.c	Thu Nov 08 16:45:54 2018 +0300
+++ b/njs/njs_vm.c	Fri Nov 09 18:05:39 2018 +0300
@@ -1519,9 +1519,14 @@ njs_vmcode_not_equal(njs_vm_t *vm, njs_v
 static nxt_noinline njs_ret_t
 njs_values_equal(njs_vm_t *vm, const njs_value_t *val1, const njs_value_t *val2)
 {
+    nxt_bool_t  nv1, nv2;
+
+    nv1 = njs_is_null_or_void(val1);
+    nv2 = njs_is_null_or_void(val2);
+
     /* Void and null are equal and not comparable with anything else. */
-    if (njs_is_null_or_void(val1)) {
-        return (njs_is_null_or_void(val2));
+    if (nv1 || nv2) {
+        return (nv1 && nv2);
     }
 
     if (njs_is_numeric(val1) && njs_is_numeric(val2)) {
diff -r c5a3ac902bc2 -r abec5f8d55a1 njs/test/njs_unit_test.c
--- a/njs/test/njs_unit_test.c	Thu Nov 08 16:45:54 2018 +0300
+++ b/njs/test/njs_unit_test.c	Fri Nov 09 18:05:39 2018 +0300
@@ -1025,6 +1025,9 @@ static njs_unit_test_t  njs_test[] =
     { nxt_string("null == false"),
       nxt_string("false") },
 
+    { nxt_string("0 == null"),
+      nxt_string("false") },
+
     { nxt_string("!null"),
       nxt_string("true") },