From: Tom Gundersen <teg@jklm.no>
Date: Fri, 15 May 2015 23:07:45 +0000 (+0200)
Subject: util: loop_write - accept 0-length message
X-Git-Tag: v226.4~1^2~381
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=6ec9b87c4ecf5144b5ea845a53a352dd9f2d173a;hp=d2febf7f92eba0919773ce93d80df50fd3faeb5d;p=elogind.git

util: loop_write - accept 0-length message

write() can send empty messages, so make sure loop_write() can do the same.
---

diff --git a/src/shared/util.c b/src/shared/util.c
index d7a5b2094..d3dacfcfb 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1665,7 +1665,7 @@ int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
 
         errno = 0;
 
-        while (nbytes > 0) {
+        do {
                 ssize_t k;
 
                 k = write(fd, p, nbytes);
@@ -1685,12 +1685,12 @@ int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
                         return -errno;
                 }
 
-                if (k == 0) /* Can't really happen */
+                if (nbytes > 0 && k == 0) /* Can't really happen */
                         return -EIO;
 
                 p += k;
                 nbytes -= k;
-        }
+        } while (nbytes > 0);
 
         return 0;
 }