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, 9 insertions, 6 deletions

diff --git a/src/java_uescape.cc b/src/java_uescape.cc
index 925b050..3951b5f 100644
--- a/src/java_uescape.cc
+++ b/src/java_uescape.cc
@@ -46,9 +46,8 @@ class UnicodeEscapeReader {
     if (fill_ == 0) {
       // Optimize for the case when there are no unicode escapes.
       auto ret = reader_->read(dst, max);
-      if (!ret.has_value() || ret.value() == 0) {
+      if (!ret.has_value())
         return ret;
-      }
 
       eof = false;
       state.rstart = reinterpret_cast<T*>(dst);
@@ -63,10 +62,14 @@ class UnicodeEscapeReader {
       auto ret = reader_->read(buffer_.get() + fill_,
                                (kBufferSize - fill_) * sizeof(T));
       if (!ret.has_value()) {
-        return ret;
+        if (ret.error() != io::ReadError::Eof) {
+          return ret;
+        }
+        eof = true;
+      } else {
+        eof = false;
+        fill_ += ret.value() / sizeof(T);
       }
-      eof = ret.value() == 0;
-      fill_ += ret.value() / sizeof(T);
 
       state.rstart = buffer_.get();
       state.rend = buffer_.get() + fill_;
@@ -228,7 +231,7 @@ class UnicodeEscapeReader {
       fill_ += avail;
     }
 
-    // We can't return zero, that is treated as EOF, we need to read more.
+    // We shouldn't return zero, we should read more if we can.
     if (state.wptr == state.wstart) {
       if (fill_ > 0) {
         return read(state.wstart, (state.wend - state.wstart) * sizeof(T));