address requested changes

include/lo2s/ringbuf.hpp

@@ -163,6 +163,11 @@ class RingBufWriter : public ShmRingbuf
 
     std::byte* reserve(size_t ev_size)
     {
+        if (ev_size == 0)
+        {
+            return nullptr;
+        }
+
         // No other reservation can be active!
         assert(reserved_size_ == 0);
 
@@ -201,6 +206,11 @@ class RingBufReader : public ShmRingbuf
 
     std::byte* get(size_t size)
     {
+        if (size == 0)
+        {
+            return nullptr;
+        }
+
         if (!can_be_loaded(size))
         {
             return nullptr;
@@ -210,6 +220,11 @@ class RingBufReader : public ShmRingbuf
 
     void pop(size_t ev_size)
     {
+        if (ev_size == 0)
+        {
+            return;
+        }
+
         // Calling pop() without trying to get() data from the ringbuffer first is an error
         assert(can_be_loaded(ev_size));
 

src/monitor/process_monitor_main.cpp

@@ -119,7 +119,7 @@ static void drop_privileges()
     assert(getgid() != 0);
 }
 
-std::vector<char*> to_vector_of_c_str(std::vector<std::string> vec)
+std::vector<char*> to_vector_of_c_str(const std::vector<std::string> vec)
 {
     std::vector<char*> res;
     std::transform(vec.begin(), vec.end(), std::back_inserter(res), [](const std::string& s) {