Fixed memory leak on zmq_sendmsg failure

- when this call fails, caller has to use zmq_msg_close() to
  avoid memory leak on messages larger than 30 bytes

doc/zlog.txt

@@ -8,6 +8,44 @@ zlog - logging class
 SYNOPSIS
 --------
 ----
+//  Constructor; the sender name is prepended to every message, and may
+//  not be null.
+CZMQ_EXPORT zlog_t *
+    zlog_new (const char *sender);
+
+//  Destructor
+CZMQ_EXPORT void
+    zlog_destroy (zlog_t **self_p);
+
+//  Set foreground logging on/off. By default, this is off on systems that
+//  can do background logging using syslog, and on for systems without syslog
+//  support.
+CZMQ_EXPORT void
+    zlog_set_foreground (zlog_t *self, bool foreground);
+
+//  Log error condition - highest priority
+CZMQ_EXPORT void
+    zlog_error (zlog_t *self, const char *format, ...);
+
+//  Log warning condition - high priority
+CZMQ_EXPORT void
+    zlog_warning (zlog_t *self, const char *format, ...);
+
+//  Log normal, but significant, condition - normal priority
+CZMQ_EXPORT void
+    zlog_notice (zlog_t *self, const char *format, ...);
+
+//  Log informational message - low priority
+CZMQ_EXPORT void
+    zlog_info (zlog_t *self, const char *format, ...);
+
+//  Log debug-level message - lowest priority
+CZMQ_EXPORT void
+    zlog_debug (zlog_t *self, const char *format, ...);
+
+//  Self test of this class
+CZMQ_EXPORT int
+    zlog_test (bool verbose);
 ----
 
 DESCRIPTION
@@ -23,7 +61,15 @@ EXAMPLE
 ----
     zlog_t *log = zlog_new ("zlog_test");
     assert (log);
-    zlog_info (log, "%s, %s", "Hello", "World");
+    zlog_error   (log, "%s", "My pizza was stolen!");
+    zlog_warning (log, "%s", "My pizza is late :(");
+    zlog_notice  (log, "%s", "My pizza arrived on time");
+    zlog_info    (log, "%s", "My pizza smells great!");
+    zlog_debug   (log, "%s", "My pizza is round and flat");
+    if (verbose) {
+        zlog_set_foreground (log, true);
+        zlog_notice (log, "%s", "My pizza arrived on time");
+    }
     zlog_destroy (&log);
 ----
 

src/zframe.c

@@ -159,8 +159,10 @@ zframe_send (zframe_t **self_p, void *zocket, int flags)
             zmq_msg_init (&copy);
             if (zmq_msg_copy (&copy, &self->zmsg))
                 return -1;
-            if (zmq_sendmsg (zocket, &copy, send_flags) == -1)
+            if (zmq_sendmsg (zocket, &copy, send_flags) == -1) {
+                zmq_msg_close (&copy);
                 return -1;
+            }
         }
         else {
             int rc = zmq_sendmsg (zocket, &self->zmsg, send_flags);

src/zproxy.c

@@ -173,10 +173,13 @@ s_proxy_task (void *args, zctx_t *ctx, void *command_pipe)
                         zmq_msg_t dup;
                         zmq_msg_init (&dup);
                         zmq_msg_copy (&dup, &msg);
-                        zmq_sendmsg (capture, &dup, send_flags);
+                        if (zmq_sendmsg (capture, &dup, send_flags))
+                            zmq_msg_close (&dup);
+                    }
+                    if (zmq_sendmsg (output, &msg, send_flags) == -1) {
+                        zmq_msg_close (&msg);
+                        break;
                     }
-                    int rc = zmq_sendmsg (output, &msg, send_flags);
-                    assert (rc != -1);
                     if (zmq_recvmsg (which, &msg, ZMQ_DONTWAIT) == -1)
                         break;      //  Presumably EAGAIN
                     send_flags = zsocket_rcvmore (which)? ZMQ_SNDMORE: 0;

src/zsocket.c

@@ -199,9 +199,9 @@ zsocket_type_str (void *self)
 //  Accepts these flags: ZFRAME_MORE and ZFRAME_DONTWAIT.
 
 int
-zsocket_sendmem (void *socket, const void *data, size_t size, int flags)
+zsocket_sendmem (void *zocket, const void *data, size_t size, int flags)
 {
-    assert (socket);
+    assert (zocket);
     assert (size == 0 || data);
 
     int snd_flags = (flags & ZFRAME_MORE)? ZMQ_SNDMORE : 0;
@@ -211,8 +211,12 @@ zsocket_sendmem (void *socket, const void *data, size_t size, int flags)
     zmq_msg_init_size (&msg, size);
     memcpy (zmq_msg_data (&msg), data, size);
 
-    int rc = zmq_sendmsg (socket, &msg, snd_flags);
-    return rc == -1? -1: 0;
+    if (zmq_sendmsg (zocket, &msg, snd_flags) == -1) {
+        zmq_msg_close (&msg);
+        return -1;
+    }
+    else
+        return 0;
 }
 
 
@@ -226,8 +230,12 @@ zsocket_signal (void *zocket)
 {
     zmq_msg_t msg;
     zmq_msg_init_size (&msg, 0);
-    int rc = zmq_sendmsg (zocket, &msg, 0);
-    return rc == -1? -1: 0;
+    if (zmq_sendmsg (zocket, &msg, 0) == -1) {
+        zmq_msg_close (&msg);
+        return -1;
+    }
+    else
+        return 0;
 }
 
 
@@ -241,8 +249,10 @@ zsocket_wait (void *zocket)
 {
     zmq_msg_t msg;
     zmq_msg_init (&msg);
-    int rc = zmq_recvmsg (zocket, &msg, 0);
-    return rc == -1? -1: 0;
+    if (zmq_recvmsg (zocket, &msg, 0) == -1)
+        return -1;
+    else
+        return 0;
 }
 
 

src/zstr.c

@@ -44,9 +44,12 @@ s_send_string (void *socket, bool more, char *string)
     zmq_msg_t message;
     zmq_msg_init_size (&message, len);
     memcpy (zmq_msg_data (&message), string, len);
-    int rc = zmq_sendmsg (socket, &message, more? ZMQ_SNDMORE: 0);
-
-    return rc == -1? -1: 0;
+    if (zmq_sendmsg (socket, &message, more? ZMQ_SNDMORE: 0)) {
+        zmq_msg_close (&message);
+        return -1;
+    }
+    else
+        return 0;
 }