Fix http_parser.nread off-by-one accounting error.

Fixes: https://github.com/nodejs/http-parser/issues/426
PR-URL: https://github.com/nodejs/http-parser/pull/427
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

http_parser.c

@@ -1339,13 +1339,14 @@ reexecute:
           }
         }
 
-        COUNT_HEADER_SIZE(p - start);
-
         if (p == data + len) {
           --p;
+          COUNT_HEADER_SIZE(p - start);
           break;
         }
 
+        COUNT_HEADER_SIZE(p - start);
+
         if (ch == ':') {
           UPDATE_STATE(s_header_value_discard_ws);
           CALLBACK_DATA(header_field);
@@ -1634,10 +1635,10 @@ reexecute:
         }
         parser->header_state = h_state;
 
-        COUNT_HEADER_SIZE(p - start);
-
         if (p == data + len)
           --p;
+
+        COUNT_HEADER_SIZE(p - start);
         break;
       }
 

test.c

@@ -3388,8 +3388,17 @@ test_message (const struct message *message)
     size_t msg2len = raw_len - msg1len;
 
     if (msg1len) {
+      assert(num_messages == 0);
+      messages[0].headers_complete_cb_called = FALSE;
+
       read = parse(msg1, msg1len);
 
+      if (!messages[0].headers_complete_cb_called && parser.nread != read) {
+        assert(parser.nread == read);
+        print_error(msg1, read);
+        abort();
+      }
+
       if (message->upgrade && parser.upgrade && num_messages > 0) {
         messages[num_messages - 1].upgrade = msg1 + read;
         goto test;
@@ -3898,8 +3907,16 @@ test_scan (const struct message *r1, const struct message *r2, const struct mess
         strlncpy(buf3, sizeof(buf1), total+j, buf3_len);
         buf3[buf3_len] = 0;
 
+        assert(num_messages == 0);
+        messages[0].headers_complete_cb_called = FALSE;
+
         read = parse(buf1, buf1_len);
 
+        if (!messages[0].headers_complete_cb_called && parser.nread != read) {
+          print_error(buf1, read);
+          goto error;
+        }
+
         if (parser.upgrade) goto test;
 
         if (read != buf1_len) {