diff -r c374d11d6720 -r 7fe53d5d587c src/server/util/io.c
--- a/src/server/util/io.c	Mon Feb 11 09:18:33 2019 +0100
+++ b/src/server/util/io.c	Fri Aug 02 22:40:02 2019 +0200
@@ -521,10 +521,16 @@
         char *write_buf = buf;
         while(r > 0) {
             ssize_t w = fd->write(fd, write_buf, r);
+            if(w <= 0) {
+                break;
+            }
             r -= w;
             length -= w;
             write_buf += w;
         }
+        if(r > 0) {
+            break;
+        }
     }
     free(buf);
     if(length > 0) {