*
* This creates a plan to read data into a buffer. Once it's all
* read, the @next function will be called: on an error, the finish
- * function is called instead.
+ * function is called instead. If read() returns 0 (EOF) errno is set
+ * to 0.
*
* Note that the I/O may actually be done immediately.
*
*
* This creates a plan to read data into a buffer. Once any data is
* read, @len is updated and the @next function will be called: on an
- * error, the finish function is called instead.
+ * error, the finish function is called instead. If read() returns 0 (EOF)
+ * errno is set to 0.
*
* Note that the I/O may actually be done immediately.
*