When there is an error reading a line of input, return the actual number of

characters received before the error (not a whole buffer full of junk!)

src/newlib/genstd.c

@@ -80,7 +80,7 @@ static _ssize_t std_read( struct _reent *r, int fd, void* vptr, size_t len )
     }
     ptr[ i ++ ] = c;
   }
-  return len;
+  return i;
 }
 
 // 'write'