bugfix: mark committed to false only when it is nil in conn

lib/resty/limit/conn.lua

@@ -46,7 +46,9 @@ function _M.incoming(self, key, commit)
     local dict = self.dict
     local max = self.max
 
-    self.committed = false
+    if self.committed == nil then
+        self.committed = false
+    end
 
     local conn, err
     if commit then

lib/resty/limit/conn.md

@@ -193,7 +193,8 @@ key so that we can avoid a single client from flooding our service with too many
 does not prefix nor suffix the user key so it is the user's responsibility to ensure the key
 is unique in the `lua_shared_dict` shm zone).
 * `commit` is a boolean value. If set to `true`, the object will actually record the event
-in the shm zone backing the current object; otherwise it would just be a "dry run" (which is the default).
+in the shm zone backing the current object; otherwise it would just be a "dry run" (which is the default),
+which does not change the committed state.
 
 The return values depend on the following cases:
 

t/conn.t

@@ -114,23 +114,23 @@ committed: false
 3: 0, conn: 1
 committed: true
 4: 0, conn: 2
-committed: false
+committed: true
 5: 0, conn: 2
 committed: true
 6: 1, conn: 3
-committed: false
+committed: true
 7: 1, conn: 3
-committed: false
+committed: true
 8: 1, conn: 3
-committed: false
+committed: true
 9: 1, conn: 3
-committed: false
+committed: true
 10: 1, conn: 3
-committed: false
+committed: true
 11: 1, conn: 3
-committed: false
+committed: true
 12: 1, conn: 3
-committed: false
+committed: true
 --- no_error_log
 [error]
 [lua]
@@ -285,3 +285,43 @@ failed to limit conn: rejected
 --- no_error_log
 [error]
 [lua]
+
+
+
+=== TEST 6: incoming dry run shall not modify committed state
+--- http_config eval
+"
+$::HttpConfig
+
+    lua_shared_dict store 1m;
+"
+--- config
+    location = /t {
+        content_by_lua_block {
+            local limit_conn = require "resty.limit.conn"
+            local lim = limit_conn.new("store", 2, 1, 1)
+            ngx.shared.store:flush_all()
+            local key = "foo"
+
+            local delay, err = lim:incoming(key, true)
+            if not delay then
+                ngx.say("failed to limit conn: ", err)
+            end
+            delay, err = lim:incoming(key, false)
+            if not delay then
+                ngx.say("failed to limit conn: ", err)
+            end
+            if not lim:is_committed() then
+                ngx.say("not committed")
+            else
+                ngx.say("committed")
+            end
+        }
+    }
+--- request
+    GET /t
+--- response_body
+committed
+--- no_error_log
+[error]
+[lua]