From b74583ee6da1d3e0a87fe75f2bd0f3d73ae02439 Mon Sep 17 00:00:00 2001
From: Igor Sysoev <igor@sysoev.ru>
Date: Tue, 11 Oct 2016 17:04:28 +0300
Subject: [PATCH] Segfaults in increment and decrement operators have been
 fixed.

---
 njs/njs_generator.c      | 4 +++-
 njs/test/njs_unit_test.c | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/njs/njs_generator.c b/njs/njs_generator.c
index 72bc6e98..a262638e 100644
--- a/njs/njs_generator.c
+++ b/njs/njs_generator.c
@@ -21,6 +21,7 @@
 #include <njs_variable.h>
 #include <njs_parser.h>
 #include <string.h>
+#include <stdio.h>
 
 
 static nxt_int_t njs_generator(njs_vm_t *vm, njs_parser_t *parser,
@@ -1848,7 +1849,8 @@ njs_generate_inc_dec_operation(njs_vm_t *vm, njs_parser_t *parser,
     if (node->dest != NULL) {
         dest_index = node->dest->index;
 
-        if (dest_index != lvalue->left->index
+        if (dest_index != NJS_INDEX_NONE
+            && dest_index != lvalue->left->index
             && dest_index != lvalue->right->index)
         {
             node->index = dest_index;
diff --git a/njs/test/njs_unit_test.c b/njs/test/njs_unit_test.c
index c0e700fc..f1e9fa86 100644
--- a/njs/test/njs_unit_test.c
+++ b/njs/test/njs_unit_test.c
@@ -471,6 +471,9 @@ static njs_unit_test_t  njs_test[] =
     { nxt_string("[[]+[]]-[]+[[]-[]]"),
       nxt_string("00") },
 
+    { nxt_string("!--[][1]"),
+      nxt_string("true") },
+
     { nxt_string("'true' == true"),
       nxt_string("false") },
 
-- 
2.47.3