Fix zero length chunked response regression (#256)

* Add test case for zero length chunked response

* add fix

* limit scope

* tidy

* fix test

* fix test

Author: bdraco

src/native/http.c

@@ -62,7 +62,8 @@ int llhttp__after_headers_complete(llhttp_t* parser, const char* p,
         parser->status_code == 102 ||     /* Processing */
         parser->status_code == 103 ||     /* Early Hints */
         parser->status_code == 204 ||     /* No Content */
-        parser->status_code == 304        /* Not Modified */
+        (parser->status_code == 304 &&
+         !(parser->flags & F_CHUNKED)) /* Not Modified */
       )
     )
   ) {

test/response/connection.md

@@ -503,6 +503,8 @@ off=94 message complete
 HTTP/1.1 304 Not Modified
 Transfer-Encoding: chunked
 
+0
+
 HTTP/1.1 200 OK
 Transfer-Encoding: chunked
 
@@ -523,22 +525,24 @@ off=45 header_field complete
 off=46 len=7 span[header_value]="chunked"
 off=55 header_value complete
 off=57 headers complete status=304 v=1/1 flags=208 content_length=0
-off=57 message complete
-off=57 reset
-off=57 message begin
-off=62 len=3 span[version]="1.1"
-off=65 version complete
-off=70 len=2 span[status]="OK"
-off=74 status complete
-off=74 len=17 span[header_field]="Transfer-Encoding"
-off=92 header_field complete
-off=93 len=7 span[header_value]="chunked"
-off=102 header_value complete
-off=104 headers complete status=200 v=1/1 flags=208 content_length=0
-off=107 chunk header len=5
-off=107 len=5 span[body]="hello"
-off=114 chunk complete
-off=117 chunk header len=0
+off=60 chunk header len=0
+off=62 chunk complete
+off=62 message complete
+off=62 reset
+off=62 message begin
+off=67 len=3 span[version]="1.1"
+off=70 version complete
+off=75 len=2 span[status]="OK"
+off=79 status complete
+off=79 len=17 span[header_field]="Transfer-Encoding"
+off=97 header_field complete
+off=98 len=7 span[header_value]="chunked"
+off=107 header_value complete
+off=109 headers complete status=200 v=1/1 flags=208 content_length=0
+off=112 chunk header len=5
+off=112 len=5 span[body]="hello"
+off=119 chunk complete
+off=122 chunk header len=0
 ```
 
 ## HTTP 100 first, then 400

test/response/transfer-encoding.md

@@ -408,3 +408,30 @@ off=67 len=1 span[body]=cr
 off=68 len=1 span[body]=lf
 ```
 
+## Zero length chunked can be parsed
+
+<!-- meta={"type": "response" } -->
+```http
+HTTP/1.1 304 Not Modified
+Transfer-Encoding: chunked
+
+0
+
+
+```
+
+```log
+off=0 message begin
+off=5 len=3 span[version]="1.1"
+off=8 version complete
+off=13 len=12 span[status]="Not Modified"
+off=27 status complete
+off=27 len=17 span[header_field]="Transfer-Encoding"
+off=45 header_field complete
+off=46 len=7 span[header_value]="chunked"
+off=55 header_value complete
+off=57 headers complete status=304 v=1/1 flags=208 content_length=0
+off=60 chunk header len=0
+off=62 chunk complete
+off=62 message complete
+```