core, plugins: fix conditions to insert elements in linked lists

This removes scan-build warnings about dereference of last_xxx null pointers.

src/core/wee-config-file.c

@@ -166,7 +166,7 @@ config_file_new (struct t_weechat_plugin *plugin, const char *name,
 
         new_config_file->prev_config = last_config_file;
         new_config_file->next_config = NULL;
-        if (config_files)
+        if (last_config_file)
             last_config_file->next_config = new_config_file;
         else
             config_files = new_config_file;
@@ -286,7 +286,7 @@ config_file_new_section (struct t_config_file *config_file, const char *name,
 
         new_section->prev_section = config_file->last_section;
         new_section->next_section = NULL;
-        if (config_file->sections)
+        if (config_file->last_section)
             config_file->last_section->next_section = new_section;
         else
             config_file->sections = new_section;

src/core/wee-config.c

@@ -1705,10 +1705,10 @@ config_weechat_proxy_read_cb (const void *pointer, void *data,
             /* add new proxy at the end */
             ptr_temp_proxy->prev_proxy = last_weechat_temp_proxy;
             ptr_temp_proxy->next_proxy = NULL;
-            if (!weechat_temp_proxies)
-                weechat_temp_proxies = ptr_temp_proxy;
-            else
+            if (last_weechat_temp_proxy)
                 last_weechat_temp_proxy->next_proxy = ptr_temp_proxy;
+            else
+                weechat_temp_proxies = ptr_temp_proxy;
             last_weechat_temp_proxy = ptr_temp_proxy;
         }
     }
@@ -1785,10 +1785,10 @@ config_weechat_bar_read_cb (const void *pointer, void *data,
             /* add new bar at the end */
             ptr_temp_bar->prev_bar = last_gui_temp_bar;
             ptr_temp_bar->next_bar = NULL;
-            if (!gui_temp_bars)
-                gui_temp_bars = ptr_temp_bar;
-            else
+            if (last_gui_temp_bar)
                 last_gui_temp_bar->next_bar = ptr_temp_bar;
+            else
+                gui_temp_bars = ptr_temp_bar;
             last_gui_temp_bar = ptr_temp_bar;
         }
     }

src/core/wee-infolist.c

@@ -57,7 +57,7 @@ infolist_new (struct t_weechat_plugin *plugin)
 
         new_infolist->prev_infolist = last_weechat_infolist;
         new_infolist->next_infolist = NULL;
-        if (weechat_infolists)
+        if (last_weechat_infolist)
             last_weechat_infolist->next_infolist = new_infolist;
         else
             weechat_infolists = new_infolist;
@@ -114,7 +114,7 @@ infolist_new_item (struct t_infolist *infolist)
 
         new_item->prev_item = infolist->last_item;
         new_item->next_item = NULL;
-        if (infolist->items)
+        if (infolist->last_item)
             infolist->last_item->next_item = new_item;
         else
             infolist->items = new_item;
@@ -150,7 +150,7 @@ infolist_new_var_integer (struct t_infolist_item *item,
 
         new_var->prev_var = item->last_var;
         new_var->next_var = NULL;
-        if (item->vars)
+        if (item->last_var)
             item->last_var->next_var = new_var;
         else
             item->vars = new_var;
@@ -184,7 +184,7 @@ infolist_new_var_string (struct t_infolist_item *item,
 
         new_var->prev_var = item->last_var;
         new_var->next_var = NULL;
-        if (item->vars)
+        if (item->last_var)
             item->last_var->next_var = new_var;
         else
             item->vars = new_var;
@@ -218,7 +218,7 @@ infolist_new_var_pointer (struct t_infolist_item *item,
 
         new_var->prev_var = item->last_var;
         new_var->next_var = NULL;
-        if (item->vars)
+        if (item->last_var)
             item->last_var->next_var = new_var;
         else
             item->vars = new_var;
@@ -255,7 +255,7 @@ infolist_new_var_buffer (struct t_infolist_item *item,
 
         new_var->prev_var = item->last_var;
         new_var->next_var = NULL;
-        if (item->vars)
+        if (item->last_var)
             item->last_var->next_var = new_var;
         else
             item->vars = new_var;
@@ -291,7 +291,7 @@ infolist_new_var_time (struct t_infolist_item *item,
 
         new_var->prev_var = item->last_var;
         new_var->next_var = NULL;
-        if (item->vars)
+        if (item->last_var)
             item->last_var->next_var = new_var;
         else
             item->vars = new_var;

src/core/wee-proxy.c

@@ -403,7 +403,7 @@ proxy_new_with_options (const char *name,
 
     /* add proxy to proxies list */
     new_proxy->prev_proxy = last_weechat_proxy;
-    if (weechat_proxies)
+    if (last_weechat_proxy)
         last_weechat_proxy->next_proxy = new_proxy;
     else
         weechat_proxies = new_proxy;

src/core/wee-upgrade-file.c

@@ -245,7 +245,7 @@ upgrade_file_new (const char *filename,
         /* add upgrade file to list of upgrade files */
         new_upgrade_file->prev_upgrade = last_upgrade_file;
         new_upgrade_file->next_upgrade = NULL;
-        if (upgrade_files)
+        if (last_upgrade_file)
             last_upgrade_file->next_upgrade = new_upgrade_file;
         else
             upgrade_files = new_upgrade_file;

src/gui/gui-bar-item.c

@@ -557,7 +557,7 @@ gui_bar_item_new (struct t_weechat_plugin *plugin, const char *name,
 
         /* add bar item to bar items queue */
         new_bar_item->prev_item = last_gui_bar_item;
-        if (gui_bar_items)
+        if (last_gui_bar_item)
             last_gui_bar_item->next_item = new_bar_item;
         else
             gui_bar_items = new_bar_item;

src/gui/gui-buffer.c

@@ -501,7 +501,7 @@ gui_buffer_insert (struct t_gui_buffer *buffer)
         }
         buffer->prev_buffer = last_gui_buffer;
         buffer->next_buffer = NULL;
-        if (gui_buffers)
+        if (last_gui_buffer)
             last_gui_buffer->next_buffer = buffer;
         else
             gui_buffers = buffer;
@@ -3670,7 +3670,7 @@ gui_buffer_sort_by_layout_number ()
             /* move the buffer in a temporary list */
             ptr_buffer->prev_buffer = last_extra_buffer;
             ptr_buffer->next_buffer = NULL;
-            if (extra_buffers)
+            if (last_extra_buffer)
                 last_extra_buffer->next_buffer = ptr_buffer;
             else
                 extra_buffers = ptr_buffer;
@@ -3807,7 +3807,7 @@ gui_buffer_undo_add (struct t_gui_buffer *buffer)
     /* add undo to the list */
     new_undo->prev_undo = buffer->last_input_undo;
     new_undo->next_undo = NULL;
-    if (buffer->input_undo)
+    if (buffer->last_input_undo)
         (buffer->last_input_undo)->next_undo = new_undo;
     else
         buffer->input_undo = new_undo;
@@ -4014,7 +4014,7 @@ gui_buffer_visited_add (struct t_gui_buffer *buffer)
 
         new_buffer_visited->prev_buffer = last_gui_buffer_visited;
         new_buffer_visited->next_buffer = NULL;
-        if (gui_buffers_visited)
+        if (last_gui_buffer_visited)
             last_gui_buffer_visited->next_buffer = new_buffer_visited;
         else
             gui_buffers_visited = new_buffer_visited;

src/gui/gui-filter.c

@@ -417,7 +417,7 @@ gui_filter_new (int enabled, const char *name, const char *buffer_name,
 
         /* add filter to filters list */
         new_filter->prev_filter = last_gui_filter;
-        if (gui_filters)
+        if (last_gui_filter)
             last_gui_filter->next_filter = new_filter;
         else
             gui_filters = new_filter;

src/gui/gui-layout.c

@@ -122,7 +122,7 @@ gui_layout_add (struct t_gui_layout *layout)
 
     layout->prev_layout = last_gui_layout;
     layout->next_layout = NULL;
-    if (gui_layouts)
+    if (last_gui_layout)
         last_gui_layout->next_layout = layout;
     else
         gui_layouts = layout;
@@ -234,7 +234,7 @@ gui_layout_buffer_add (struct t_gui_layout *layout,
 
         /* add layout buffer to list */
         new_layout_buffer->prev_layout = layout->last_layout_buffer;
-        if (layout->layout_buffers)
+        if (layout->last_layout_buffer)
             (layout->last_layout_buffer)->next_layout = new_layout_buffer;
         else
             layout->layout_buffers = new_layout_buffer;

src/gui/gui-line.c

@@ -937,10 +937,10 @@ gui_line_add_to_list (struct t_gui_lines *lines,
 {
     int prefix_length, prefix_is_nick;
 
-    if (!lines->first_line)
-        lines->first_line = line;
-    else
+    if (lines->last_line)
         (lines->last_line)->next_line = line;
+    else
+        lines->first_line = line;
     line->prev_line = lines->last_line;
     line->next_line = NULL;
     lines->last_line = line;

src/gui/gui-window.c

@@ -678,7 +678,7 @@ gui_window_new (struct t_gui_window *parent_window, struct t_gui_buffer *buffer,
 
     /* add window to windows queue */
     new_window->prev_window = last_gui_window;
-    if (gui_windows)
+    if (last_gui_window)
         last_gui_window->next_window = new_window;
     else
         gui_windows = new_window;

src/plugins/exec/exec.c

@@ -136,7 +136,7 @@ exec_add ()
 
     new_exec_cmd->prev_cmd = last_exec_cmd;
     new_exec_cmd->next_cmd = NULL;
-    if (exec_cmds)
+    if (last_exec_cmd)
         last_exec_cmd->next_cmd = new_exec_cmd;
     else
         exec_cmds = new_exec_cmd;

src/plugins/irc/irc-channel.c

@@ -486,7 +486,7 @@ irc_channel_new (struct t_irc_server *server, int channel_type,
     /* add new channel to channels list */
     new_channel->prev_channel = server->last_channel;
     new_channel->next_channel = NULL;
-    if (server->channels)
+    if (server->last_channel)
         (server->last_channel)->next_channel = new_channel;
     else
         server->channels = new_channel;

src/plugins/irc/irc-ignore.c

@@ -152,7 +152,7 @@ irc_ignore_new (const char *mask, const char *server, const char *channel)
 
         /* add ignore to ignore list */
         new_ignore->prev_ignore = last_irc_ignore;
-        if (irc_ignore_list)
+        if (last_irc_ignore)
             last_irc_ignore->next_ignore = new_ignore;
         else
             irc_ignore_list = new_ignore;

src/plugins/irc/irc-nick.c

@@ -528,7 +528,7 @@ irc_nick_new (struct t_irc_server *server, struct t_irc_channel *channel,
 
     /* add nick to end of list */
     new_nick->prev_nick = channel->last_nick;
-    if (channel->nicks)
+    if (channel->last_nick)
         channel->last_nick->next_nick = new_nick;
     else
         channel->nicks = new_nick;

src/plugins/irc/irc-notify.c

@@ -208,7 +208,7 @@ irc_notify_new (struct t_irc_server *server, const char *nick, int check_away)
 
         /* add notify to notify list on server */
         new_notify->prev_notify = server->last_notify;
-        if (server->notify_list)
+        if (server->last_notify)
             server->last_notify->next_notify = new_notify;
         else
             server->notify_list = new_notify;

src/plugins/irc/irc-raw.c

@@ -205,7 +205,7 @@ irc_raw_message_add_to_list (time_t date, const char *prefix,
         /* add message to list */
         new_raw_message->prev_message = last_irc_raw_message;
         new_raw_message->next_message = NULL;
-        if (irc_raw_messages)
+        if (last_irc_raw_message)
             last_irc_raw_message->next_message = new_raw_message;
         else
             irc_raw_messages = new_raw_message;

src/plugins/irc/irc-redirect.c

@@ -325,7 +325,7 @@ irc_redirect_pattern_new (const char *name, int temp_pattern, int timeout,
 
     /* add redirect pattern to end of list */
     new_redirect_pattern->prev_redirect = last_irc_redirect_pattern;
-    if (irc_redirect_patterns)
+    if (last_irc_redirect_pattern)
         last_irc_redirect_pattern->next_redirect = new_redirect_pattern;
     else
         irc_redirect_patterns = new_redirect_pattern;
@@ -484,7 +484,7 @@ irc_redirect_new_with_commands (struct t_irc_server *server,
 
     /* add redirect to end of list */
     new_redirect->prev_redirect = server->last_redirect;
-    if (server->redirects)
+    if (server->last_redirect)
         (server->last_redirect)->next_redirect = new_redirect;
     else
         server->redirects = new_redirect;

src/plugins/irc/irc-server.c

@@ -1129,7 +1129,7 @@ irc_server_alloc (const char *name)
     /* add new server to queue */
     new_server->prev_server = last_irc_server;
     new_server->next_server = NULL;
-    if (irc_servers)
+    if (last_irc_server)
         last_irc_server->next_server = new_server;
     else
         irc_servers = new_server;
@@ -1558,7 +1558,7 @@ irc_server_outqueue_add (struct t_irc_server *server, int priority,
 
         new_outqueue->prev_outqueue = server->last_outqueue[priority];
         new_outqueue->next_outqueue = NULL;
-        if (server->outqueue[priority])
+        if (server->last_outqueue[priority])
             server->last_outqueue[priority]->next_outqueue = new_outqueue;
         else
             server->outqueue[priority] = new_outqueue;

src/plugins/logger/logger-buffer.c

@@ -98,7 +98,7 @@ logger_buffer_add (struct t_gui_buffer *buffer, int log_level)
 
         new_logger_buffer->prev_buffer = last_logger_buffer;
         new_logger_buffer->next_buffer = NULL;
-        if (logger_buffers)
+        if (last_logger_buffer)
             last_logger_buffer->next_buffer = new_logger_buffer;
         else
             logger_buffers = new_logger_buffer;

src/plugins/plugin.c

@@ -904,7 +904,7 @@ plugin_load (const char *filename, int init_plugin, int argc, char **argv)
         /* add new plugin to list */
         new_plugin->prev_plugin = last_weechat_plugin;
         new_plugin->next_plugin = NULL;
-        if (weechat_plugins)
+        if (last_weechat_plugin)
             last_weechat_plugin->next_plugin = new_plugin;
         else
             weechat_plugins = new_plugin;

src/plugins/relay/relay-client.c

@@ -739,7 +739,7 @@ relay_client_outqueue_add (struct t_relay_client *client,
 
         new_outqueue->prev_outqueue = client->last_outqueue;
         new_outqueue->next_outqueue = NULL;
-        if (client->outqueue)
+        if (client->last_outqueue)
             client->last_outqueue->next_outqueue = new_outqueue;
         else
             client->outqueue = new_outqueue;

src/plugins/relay/relay-raw.c

@@ -205,7 +205,7 @@ relay_raw_message_add_to_list (time_t date, const char *prefix,
         /* add message to list */
         new_raw_message->prev_message = last_relay_raw_message;
         new_raw_message->next_message = NULL;
-        if (relay_raw_messages)
+        if (last_relay_raw_message)
             last_relay_raw_message->next_message = new_raw_message;
         else
             relay_raw_messages = new_raw_message;

src/plugins/script/script-repo.c

@@ -563,7 +563,7 @@ script_repo_add (struct t_script_repo *script)
         /* add script to the end */
         script->prev_script = last_script_repo;
         script->next_script = NULL;
-        if (scripts_repo)
+        if (last_script_repo)
             last_script_repo->next_script = script;
         else
             scripts_repo = script;

src/plugins/trigger/trigger.c

@@ -839,10 +839,10 @@ trigger_add (struct t_trigger *trigger,
         /* add trigger to end of list */
         trigger->prev_trigger = *last_list_trigger;
         trigger->next_trigger = NULL;
-        if (!*list_triggers)
-            *list_triggers = trigger;
-        else
+        if (*last_list_trigger)
             (*last_list_trigger)->next_trigger = trigger;
+        else
+            *list_triggers = trigger;
         *last_list_trigger = trigger;
     }
 }