diff --git a/src/util.c b/src/util.c
index 7c4005b..d44296e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -38,13 +38,14 @@ void strip_crlf(const char *text) {
 
 #define XIO(name, func, ...) ssize_t name(__VA_ARGS__) { \
     ssize_t ret = 0; \
-    size_t rem = len; \
+    size_t rem = len, done = 0; \
     while (rem > 0) { \
 	ret = func(fd, &line[len - rem], rem); \
+	if (ret == 0) break; \
 	if (ret < 0 && errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) return ret; \
-	if (ret > 0) rem -= ret; \
+	if (ret > 0) { rem -= ret; done += ret; } \
     } \
-    return len; \
+    return done; \
 }
 XIO(xread, read, int fd, void *line, size_t len);
 XIO(xwrite, write, int fd, const char *line, size_t len);