Do not set cookie when it is duplicated

2 files changed, 60 insertions, 4 deletions

diff --git a/lib/resty/cookie.lua b/lib/resty/cookie.lua
index a96da60..dfb8f8a 100644
--- a/lib/resty/cookie.lua
+++ b/lib/resty/cookie.lua
@@ -165,9 +165,11 @@ function _M.set(self, cookie)
 
     if set_cookie_type == "string" then
         -- only one cookie has been setted
-        t[1] = set_cookie
-        t[2] = cookie_str
-        ngx_header['Set-Cookie'] = t
+        if set_cookie ~= cookie_str then
+            t[1] = set_cookie
+            t[2] = cookie_str
+            ngx_header['Set-Cookie'] = t
+        end
     elseif set_cookie_type == "table" then
         -- more than one cookies has been setted
         local size = #set_cookie
@@ -176,6 +178,10 @@ function _M.set(self, cookie)
         -- so create a new table, copy all the values, and then set it back
         for i=1, size do
             t[i] = ngx_header['Set-Cookie'][i]
+            if t[i] == cookie_str then
+                -- new cookie is duplicated
+                return true
+            end
         end
         t[size + 1] = cookie_str
         ngx_header['Set-Cookie'] = t
diff --git a/t/sanity.t b/t/sanity.t
index 1385ebb..952b81e 100644
--- a/t/sanity.t
+++ b/t/sanity.t
@@ -5,7 +5,7 @@ use Cwd qw(cwd);
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 3 + 2);
+plan tests => repeat_each() * (blocks() * 3 + 4);
 
 my $pwd = cwd();
 
@@ -257,3 +257,53 @@ key, so use "--- raw_response_headers_like" instead
 --- raw_response_headers_like: Set-Cookie: Name=Bob; Path=/\r\nSet-Cookie: Age=20\r\nSet-Cookie: ID=0xf7898; Expires=Wed, 09 Jun 2021 10:18:14 GMT
 --- response_body
 Set cookie
+
+
+
+=== TEST 8: remove duplicated cookies in cookie:set
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua '
+            local ck = require "resty.cookie"
+            local cookie, err = ck:new()
+            if not cookie then
+                ngx.log(ngx.ERR, err)
+                return
+            end
+
+            local ok, err = cookie:set({
+                key = "Name", value = "Bob", path = "/",
+            })
+            if not ok then
+                ngx.log(ngx.ERR, err)
+                return
+            end
+
+            local ok, err = cookie:set({
+                key = "Age", value = "20",
+            })
+            if not ok then
+                ngx.log(ngx.ERR, err)
+                return
+            end
+
+            local ok, err = cookie:set({
+                key = "Name", value = "Bob", path = "/",
+            })
+            if not ok then
+                ngx.log(ngx.ERR, err)
+                return
+            end
+
+            ngx.say("Set cookie")
+        ';
+    }
+--- request
+GET /t
+--- no_error_log
+[error]
+--- raw_response_headers_like: Set-Cookie: Name=Bob; Path=/\r\nSet-Cookie: Age=20\r\n
+--- raw_response_headers_unlike: Set-Cookie: Name=Bob; Path=/\r\nSet-Cookie: Age=20\r\nSet-Cookie: Name=Bob; Path=/
+--- response_body
+Set cookie