xmppipe_send_message: fix memory leak

Fix a memory leak caused by improper usage of
xmpp_stanza_new()/xmpp_stanza_release() by replacing usage with the
simpler xmpp_message_new()/xmpp_message_set_body() API available in
libstrophe 0.9.0, as advised by @pasis.

Fixes https://github.com/msantos/xmppipe/issues/3.

src/xmppipe.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2017, Michael Santos <michael.santos@gmail.com>
+/* Copyright (c) 2015-2019, Michael Santos <michael.santos@gmail.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -145,6 +145,10 @@ char *xmppipe_strdup(const char *);
 void *xmppipe_malloc(size_t);
 void *xmppipe_calloc(size_t, size_t);
 
+xmpp_stanza_t *xmppipe_message_new(xmpp_ctx_t *ctx, const char *const type,
+                                   const char *const to, const char *const id);
+void xmppipe_message_set_body(xmpp_stanza_t *msg, const char *const text);
+
 xmpp_stanza_t *xmppipe_stanza_new(xmpp_ctx_t *);
 void xmppipe_stanza_set_attribute(xmpp_stanza_t *const, const char *const,
                                   const char *const);

src/xmppipe_send.c

@@ -135,8 +135,6 @@ XMPPIPE_DONE:
 void xmppipe_send_message(xmppipe_state_t *state, char *to, char *type,
                           char *buf, size_t len) {
   xmpp_stanza_t *message = NULL;
-  xmpp_stanza_t *body = NULL;
-  xmpp_stanza_t *text = NULL;
   char *id = NULL;
 
   id = xmpp_uuid_gen(state->ctx);
@@ -145,16 +143,7 @@ void xmppipe_send_message(xmppipe_state_t *state, char *to, char *type,
     errx(EXIT_FAILURE, "unable to allocate message id");
   }
 
-  message = xmppipe_stanza_new(state->ctx);
-  xmppipe_stanza_set_name(message, "message");
-  xmppipe_stanza_set_type(message, type);
-  xmppipe_stanza_set_attribute(message, "to", to);
-  xmppipe_stanza_set_id(message, id);
-
-  body = xmppipe_stanza_new(state->ctx);
-  xmppipe_stanza_set_name(body, "body");
-
-  text = xmppipe_stanza_new(state->ctx);
+  message = xmppipe_message_new(state->ctx, type, to, id);
 
   if (state->encode) {
     size_t len = strlen(buf);
@@ -163,17 +152,13 @@ void xmppipe_send_message(xmppipe_state_t *state, char *to, char *type,
     if (b64 == NULL)
       errx(EXIT_FAILURE, "encode: invalid input: %zu", len);
 
-    xmppipe_stanza_set_text(text, b64);
+    xmppipe_message_set_body(message, b64);
     xmpp_free(state->ctx, b64);
   } else {
-    xmppipe_stanza_set_text(text, buf);
+    xmppipe_message_set_body(message, buf);
   }
 
-  xmppipe_stanza_add_child(body, text);
-  xmppipe_stanza_add_child(message, body);
-
   xmppipe_send(state, message);
-  (void)xmpp_stanza_release(message);
   xmpp_free(state->ctx, id);
 }
 

src/xmppipe_util.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2018, Michael Santos <michael.santos@gmail.com>
+/* Copyright (c) 2015-2019, Michael Santos <michael.santos@gmail.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -94,6 +94,24 @@ void *xmppipe_calloc(size_t nmemb, size_t size) {
   return buf;
 }
 
+xmpp_stanza_t *xmppipe_message_new(xmpp_ctx_t *ctx, const char *const type,
+                                   const char *const to, const char *const id) {
+  xmpp_stanza_t *m = xmpp_message_new(ctx, type, to, id);
+
+  if (m == NULL)
+    err(3, "xmppipe_stanza_new");
+
+  return m;
+}
+
+void xmppipe_message_set_body(xmpp_stanza_t *msg, const char *const text) {
+  int rv;
+
+  rv = xmpp_message_set_body(msg, text);
+  if (rv != XMPP_EOK)
+    errx(EXIT_FAILURE, "xmpp_message_set_body: %u", rv);
+}
+
 xmpp_stanza_t *xmppipe_stanza_new(xmpp_ctx_t *ctx) {
   xmpp_stanza_t *s = xmpp_stanza_new(ctx);