http_parser: skip lws/rws in header field

[indutny]

Skip whitespace from the left and the right sides of the header field.

See: https://github.com/nodejs/node/pull/5844

cc @jasnell

[jasnell]

@indutny ... this is not working as expected. To test it, I added the following test case to test.c:

diff --git a/test.c b/test.c
index 7b01dc3..dac6997 100644
--- a/test.c
+++ b/test.c
@@ -1153,6 +1153,28 @@ const struct message requests[] =
   ,.body= ""
   }

+#if !HTTP_PARSER_STRICT
+#define WHITESPACE_IN_HEADER 42
+, {.name = "whitespace in header"
+  ,.type= HTTP_REQUEST
+  ,.raw= "GET /foo HTTP/1.1\r\n"
+         "XYZ : example.com\r\n"
+         "\r\n"
+  ,.should_keep_alive= TRUE
+  ,.message_complete_on_eof= FALSE
+  ,.http_major= 1
+  ,.http_minor= 1
+  ,.method= HTTP_GET
+  ,.request_path= "/foo"
+  ,.request_url= "/foo"
+  ,.query_string= ""
+  ,.fragment= ""
+  ,.num_headers= 1
+  ,.headers= { { "XYZ", "example.com" } }
+  ,.body= ""
+  }
+#endif
+
 , {.name= NULL } /* sentinel */
 };

Running make yields:

bash-3.2$ make
./test_g
http_parser v2.6.2 (0x020602)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay
request scan 1/4  100%
request scan 2/4  100%
request scan 3/4  100%
request scan 4/4  100%
requests okay
./test_fast
http_parser v2.6.2 (0x020602)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay

*** Error: header field in 'whitespace in header' ***

expected 'XYZ'
   found 'XYZ : example.com

'
make: *** [test] Abort trap: 6
bash-3.2$ 

Note the value for found.