Change io::Reader and company to return ReadError::Eof instead of 0.

It's debatable if Eof should be considered an error or not.
But it is pretty clear it generally is a special response that
needs special handling, so easier to keep with the unexpected lot.

Also keeps better at higher abstraction levels, such as the line
reader.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/gen_ugc.cc b/src/gen_ugc.cc
index bc7c91b..2670803 100644
--- a/src/gen_ugc.cc
+++ b/src/gen_ugc.cc
@@ -151,6 +151,8 @@ std::string_view ioerr2str(io::ReadError error) {
       return "Fatal error";
     case io::ReadError::MaxTooSmall:
       return "Too small buffer";
+    case io::ReadError::Eof:
+      return "Unexpected end of file";
   }
   std::unreachable();
 }