patch 7.4.1261

Problem:    Pending channel messages are garbage collected. Leaking memory in
            ch_sendexpr().  Leaking memory for a decoded JSON string.
Solution:   Mark the message list as used. Free the encoded JSON.  Don't save
            the JSON string.

src/channel.c

@@ -1315,4 +1315,29 @@ channel_parse_messages(void)
     return ret;
 }
 
+    int
+set_ref_in_channel(int copyID)
+{
+    int	    i;
+    int	    abort = FALSE;
+
+    for (i = 0; i < channel_count; ++i)
+    {
+	jsonq_T *head = &channels[i].ch_json_head;
+	jsonq_T *item = head->next;
+
+	while (item != head)
+	{
+	    list_T	*l = item->value->vval.v_list;
+
+	    if (l->lv_copyID != copyID)
+	    {
+		l->lv_copyID = copyID;
+		abort = abort || set_ref_in_list(l, copyID, NULL);
+	    }
+	    item = item->next;
+	}
+    }
+    return abort;
+}
 #endif /* FEAT_CHANNEL */

src/eval.c

@@ -6855,6 +6855,10 @@ garbage_collect(void)
     abort = abort || set_ref_in_python3(copyID);
 #endif
 
+#ifdef FEAT_CHANNEL
+    abort = abort || set_ref_in_channel(copyID);
+#endif
+
     if (!abort)
     {
 	/*
@@ -9842,6 +9846,7 @@ f_ch_sendexpr(typval_T *argvars, typval_T *rettv)
 	return;
 
     ch_idx = send_common(argvars, text, "sendexpr");
+    vim_free(text);
     if (ch_idx >= 0)
     {
 	if (channel_read_json_block(ch_idx, id, &listtv) == OK)

src/json.c

@@ -533,10 +533,7 @@ json_decode_string(js_read_T *reader, typval_T *res)
 	if (res != NULL)
 	{
 	    res->v_type = VAR_STRING;
-	    if (ga.ga_data == NULL)
+	    res->vval.v_string = ga.ga_data;
-		res->vval.v_string = NULL;
-	    else
-		res->vval.v_string = vim_strsave(ga.ga_data);
 	}
 	return OK;
     }

src/proto/channel.pro

@@ -22,4 +22,5 @@ int channel_poll_check(int ret_in, void *fds_in);
 int channel_select_setup(int maxfd_in, void *rfds_in);
 int channel_select_check(int ret_in, void *rfds_in);
 int channel_parse_messages(void);
+int set_ref_in_channel(int copyID);
 /* vim: set ft=c : */

src/version.c

@@ -742,6 +742,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1261,
 /**/
     1260,
 /**/