From 8ea0bb4f1c6071f9c9fc2f1181b141182e360676 Mon Sep 17 00:00:00 2001
From: Roman-Koshelev <roman.koshelev@bk.ru>
Date: Sun, 11 Apr 2021 13:15:24 +0300
Subject: [PATCH 1/2] Fix next_message_reader() method

According to the comment, the function must return a valid message
(although not necessarily complete). This is logical, but not so now.
Also, now, in the absence of a valid message, we will return a zero-size
reader pointing to the last byte
---
 include/hffix.hpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/include/hffix.hpp b/include/hffix.hpp
index 4668cfc..fdd4cd6 100644
--- a/include/hffix.hpp
+++ b/include/hffix.hpp
@@ -2069,11 +2069,13 @@ class message_reader {
         if (!is_valid_) { // this message isn't valid, so we have to try to search for the beginning of the next message.
             char const* b = buffer_ + 1;
             while(b < buffer_end_ - 10) {
-                if (!std::memcmp(b, "8=FIX", 5))
-                    break;
+                if (!std::memcmp(b, "8=FIX", 5)) {
+                    message_reader tmp(b, buffer_end_);
+                    if (tmp.is_valid()) return tmp;
+                }
                 ++b;
             }
-            return message_reader(b, buffer_end_);
+            return message_reader(buffer_end_, buffer_end_);
         }
 
         return message_reader(end_.current_.value_.end_ + 1, buffer_end_);

From 77c607ecc25b298256c5cae1bac94662ba2bdaf8 Mon Sep 17 00:00:00 2001
From: Roman-Koshelev <roman.koshelev@bk.ru>
Date: Sun, 11 Apr 2021 13:15:30 +0300
Subject: [PATCH 2/2] Add new test

---
 test/expected/writer01.fix | Bin 241 -> 275 bytes
 test/src/reader01.cpp      |   4 ++--
 test/src/writer01.cpp      |   5 ++++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/test/expected/writer01.fix b/test/expected/writer01.fix
index f7dd6d853efdba5628e35cae57826f1e8bc5430d..f12ae3cc0897c9cff0500fbb537d155f0339313f 100644
GIT binary patch
delta 41
bcmey!IGIUFPft(5!q&|*LIDShVZuiM&teKE

delta 7
OcmbQt^pSC*(nkObxdSW!

diff --git a/test/src/reader01.cpp b/test/src/reader01.cpp
index f6848ef..c38eac1 100644
--- a/test/src/reader01.cpp
+++ b/test/src/reader01.cpp
@@ -37,7 +37,7 @@ int main(int argc, char** argv)
         hffix::message_reader reader(buffer, buffer + buffer_length);
 
         // Try to read as many complete messages as there are in the buffer.
-        for (; reader.is_complete(); reader = reader.next_message_reader()) {
+        for (int i = 0; reader.is_complete(); reader = reader.next_message_reader(), ++i) {
             if (reader.is_valid()) {
 
                 // Here is a complete message. Read fields out of the reader.
@@ -98,7 +98,7 @@ int main(int argc, char** argv)
                     std::cerr << "Error reading fields: " << ex.what() << '\n';
                 }
 
-            } else {
+            } else if (i != 0) {
                 // An invalid, corrupted FIX message. Do not try to read fields
                 // out of this reader. The beginning of the invalid message is
                 // at location reader.message_begin() in the buffer, but the
diff --git a/test/src/writer01.cpp b/test/src/writer01.cpp
index c90d305..460ec93 100644
--- a/test/src/writer01.cpp
+++ b/test/src/writer01.cpp
@@ -16,8 +16,11 @@ int main(int argc, char** argv)
 
     ptime tsend(date(2017,8,9), time_duration(12,34,56));
 
+    char some_data[] = "... 8=FIX ... 8=FIX ... 8=FIX ...";
+    memcpy(buffer, some_data, sizeof(some_data));
+
     // We'll put a FIX Logon message in the buffer.
-    hffix::message_writer logon(buffer, buffer + sizeof(buffer));
+    hffix::message_writer logon(buffer + sizeof(some_data), buffer + sizeof(buffer));
 
     logon.push_back_header("FIX.4.2"); // Write BeginString and BodyLength.