fix(ui,db): harden NULL handling and resource lifecycle across UI and SQLite

ui/window: fix subwindow lifecycle (safe delwin on recreate), clamp widths, add fallback timestamp
when loading history to avoid NULL deref
ui/buffer: add GSList bounds checks; assert non-NULL timestamps when creating entries
ui/titlebar: guard newwin failures; make draw/resize/free no-ops when window is NULL
ui/statusbar: guard window creation/resize/close; clamp columns; fallback display name if JID
parsing fails
ui/inputwin: check newpad result; guard resize/getters/close on NULL; safe delwin
ui/chatwin: guard buffer_get_entry/time before ISO8601 formatting
ui/window_list: validate win_create_* results; don’t insert NULL windows; fix barejid leak in
wins_get_by_string
db/database: ensure cleanup on sqlite init/open failures; use sqlite3_close_v2 and warn if busy;
always return a ProfMessage from log_database_get_limits_info and set current UTC timestamp when
is_last with no row; initialize err_msg and free consistently; improve error messages
Prevents crashes from NULL dereferences (e.g., during MAM history) and closes small leaks; improves
robustness under OOM and allocation failures.

src/database.c

@@ -98,17 +98,23 @@ log_database_init(ProfAccount* account)
 
     auto_char char* filename = _get_db_filename(account);
     if (!filename) {
+        sqlite3_shutdown();
         return FALSE;
     }
 
     ret = sqlite3_open(filename, &g_chatlog_database);
     if (ret != SQLITE_OK) {
-        const char* err_msg = sqlite3_errmsg(g_chatlog_database);
+        const char* err_msg = g_chatlog_database ? sqlite3_errmsg(g_chatlog_database) : "(no handle)";
         log_error("Error opening SQLite database: %s", err_msg);
+        if (g_chatlog_database) {
+            sqlite3_close(g_chatlog_database);
+            g_chatlog_database = NULL;
+        }
+        sqlite3_shutdown();
         return FALSE;
     }
 
-    char* err_msg;
+    char* err_msg = NULL;
 
     int db_version = _get_db_version();
     if (db_version == latest_version) {
@@ -216,6 +222,11 @@ out:
     } else {
         log_error("Unknown SQLite error in log_database_init().");
     }
+    if (g_chatlog_database) {
+        sqlite3_close(g_chatlog_database);
+        g_chatlog_database = NULL;
+    }
+    sqlite3_shutdown();
     return FALSE;
 }
 
@@ -224,7 +235,10 @@ log_database_close(void)
 {
     log_debug("log_database_close() called");
     if (g_chatlog_database) {
-        sqlite3_close(g_chatlog_database);
+        int rc = sqlite3_close_v2(g_chatlog_database);
+        if (rc != SQLITE_OK) {
+            log_warning("sqlite3_close_v2 returned %d; database may still have active statements.", rc);
+        }
         sqlite3_shutdown();
         g_chatlog_database = NULL;
     }
@@ -281,8 +295,15 @@ log_database_get_limits_info(const gchar* const contact_barejid, gboolean is_las
 {
     sqlite3_stmt* stmt = NULL;
     const Jid* myjid = connection_get_jid();
-    if (!myjid->str)
-        return NULL;
+    // Always return a valid ProfMessage to avoid NULL dereferences in callers
+    ProfMessage* msg = message_init();
+    if (!myjid || !myjid->str) {
+        // If caller requested the last message and we have no context, fall back to now
+        if (is_last) {
+            msg->timestamp = g_date_time_new_now_utc();
+        }
+        return msg;
+    }
 
     const char* order = is_last ? "DESC" : "ASC";
     auto_sqlite char* query = sqlite3_mprintf("SELECT `archive_id`, `timestamp` FROM `ChatLogs` WHERE "
@@ -293,17 +314,21 @@ log_database_get_limits_info(const gchar* const contact_barejid, gboolean is_las
 
     if (!query) {
         log_error("Could not allocate memory for SQL query in log_database_get_limits_info()");
-        return NULL;
+        if (is_last) {
+            msg->timestamp = g_date_time_new_now_utc();
+        }
+        return msg;
     }
 
     int rc = sqlite3_prepare_v2(g_chatlog_database, query, -1, &stmt, NULL);
     if (rc != SQLITE_OK) {
-        log_error("Unknown SQLite error in log_database_get_last_info().");
-        return NULL;
+        log_error("Unknown SQLite error in log_database_get_limits_info().");
+        if (is_last) {
+            msg->timestamp = g_date_time_new_now_utc();
+        }
+        return msg;
     }
 
-    ProfMessage* msg = message_init();
-
     if (sqlite3_step(stmt) == SQLITE_ROW) {
         char* archive_id = (char*)sqlite3_column_text(stmt, 0);
         char* date = (char*)sqlite3_column_text(stmt, 1);
@@ -313,6 +338,11 @@ log_database_get_limits_info(const gchar* const contact_barejid, gboolean is_las
     }
     sqlite3_finalize(stmt);
 
+    // If nothing was found and caller expects the last message, provide a sane default
+    if (!msg->timestamp && is_last) {
+        msg->timestamp = g_date_time_new_now_utc();
+    }
+
     return msg;
 }
 

src/ui/buffer.c

@@ -140,6 +140,10 @@ void
 buffer_remove_entry(ProfBuff buffer, int entry)
 {
     GSList* node = g_slist_nth(buffer->entries, entry);
+    if (node == NULL) {
+        // Index out of range; nothing to remove
+        return;
+    }
     ProfBuffEntry* e = node->data;
     buffer->lines -= e->_lines;
     _free_entry(e);
@@ -168,6 +172,9 @@ ProfBuffEntry*
 buffer_get_entry(ProfBuff buffer, int entry)
 {
     GSList* node = g_slist_nth(buffer->entries, entry);
+    if (node == NULL) {
+        return NULL;
+    }
     return node->data;
 }
 
@@ -189,6 +196,7 @@ buffer_get_entry_by_id(ProfBuff buffer, const char* const id)
 static ProfBuffEntry*
 _create_entry(const char* show_char, int pad_indent, GDateTime* time, int flags, theme_item_t theme_item, const char* const display_from, const char* const from_jid, const char* const message, DeliveryReceipt* receipt, const char* const id, int y_start_pos, int y_end_pos)
 {
+    assert(time != NULL);
     ProfBuffEntry* e = malloc(sizeof(struct prof_buff_entry_t));
     e->show_char = STRDUP_OR_NULL(show_char);
     e->pad_indent = pad_indent;

src/ui/chatwin.c

@@ -592,8 +592,11 @@ chatwin_db_history(ProfChatWin* chatwin, const gchar* start_time, const gchar* e
 {
     auto_gchar gchar* _end_time = NULL;
     if (!end_time && buffer_size(((ProfWin*)chatwin)->layout->buffer) > 0) {
-        _end_time = g_date_time_format_iso8601(buffer_get_entry(((ProfWin*)chatwin)->layout->buffer, 0)->time);
-        end_time = _end_time;
+        ProfBuffEntry* first = buffer_get_entry(((ProfWin*)chatwin)->layout->buffer, 0);
+        if (first && first->time) {
+            _end_time = g_date_time_format_iso8601(first->time);
+            end_time = _end_time;
+        }
     }
 
     GSList* history = NULL;

src/ui/inputwin.c

@@ -163,6 +163,10 @@ create_input_window(void)
     rl_callback_handler_install(NULL, _inp_rl_linehandler);
 
     inp_win = newpad(1, INP_WIN_MAX);
+    if (!inp_win) {
+        // Failed to allocate input pad; leave inp_win NULL and avoid further use
+        return;
+    }
     wbkgd(inp_win, theme_attrs(THEME_INPUT_TEXT));
     keypad(inp_win, TRUE);
     wmove(inp_win, 0, 0);
@@ -238,6 +242,9 @@ inp_readline(void)
 void
 inp_win_resize(void)
 {
+    if (!inp_win) {
+        return;
+    }
     int col = getcurx(inp_win);
     int wcols = getmaxx(stdscr);
 
@@ -285,8 +292,10 @@ void
 inp_close(void)
 {
     rl_callback_handler_remove();
-    delwin(inp_win);
-    inp_win = NULL;
+    if (inp_win) {
+        delwin(inp_win);
+        inp_win = NULL;
+    }
     fclose(discard);
     discard = NULL;
 }
@@ -294,6 +303,9 @@ inp_close(void)
 char*
 inp_get_line(void)
 {
+    if (!inp_win) {
+        return NULL;
+    }
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
@@ -318,6 +330,9 @@ inp_set_line(const char* const new_line)
 char*
 inp_get_password(void)
 {
+    if (!inp_win) {
+        return NULL;
+    }
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();

src/ui/statusbar.c

@@ -111,16 +111,23 @@ status_bar_init(void)
 
     int row = screen_statusbar_row();
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
     statusbar_win = newwin(1, cols, row, 0);
 
-    status_bar_draw();
+    if (statusbar_win) {
+        status_bar_draw();
+    }
 }
 
 void
 status_bar_close(void)
 {
-    delwin(statusbar_win);
-    statusbar_win = NULL;
+    if (statusbar_win) {
+        delwin(statusbar_win);
+        statusbar_win = NULL;
+    }
     if (statusbar) {
         if (statusbar->time) {
             g_free(statusbar->time);
@@ -145,7 +152,13 @@ status_bar_close(void)
 void
 status_bar_resize(void)
 {
+    if (!statusbar_win) {
+        return;
+    }
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
     werase(statusbar_win);
     int row = screen_statusbar_row();
     wresize(statusbar_win, 1, cols);
@@ -285,6 +298,9 @@ status_bar_clear_fulljid(void)
 void
 status_bar_draw(void)
 {
+    if (!statusbar_win) {
+        return;
+    }
     werase(statusbar_win);
     wbkgd(statusbar_win, theme_attrs(THEME_STATUS_TEXT));
 
@@ -674,8 +690,13 @@ _display_name(StatusBarTab* tab)
         fullname = g_strconcat(mucwin_title, " conf", NULL);
     } else if (tab->window_type == WIN_PRIVATE) {
         auto_jid Jid* jid = jid_create(tab->identifier);
-        auto_gchar gchar* mucwin_title = mucwin_generate_title(jid->barejid, PREF_STATUSBAR_ROOM_TITLE);
-        fullname = g_strconcat(mucwin_title, "/", jid->resourcepart, NULL);
+        if (jid) {
+            auto_gchar gchar* mucwin_title = mucwin_generate_title(jid->barejid, PREF_STATUSBAR_ROOM_TITLE);
+            fullname = g_strconcat(mucwin_title, "/", jid->resourcepart, NULL);
+        } else {
+            // Fallback: use identifier directly if JID parsing failed
+            fullname = strdup(tab->identifier);
+        }
     } else {
         fullname = strdup("window");
     }

src/ui/titlebar.c

@@ -73,9 +73,16 @@ void
 create_title_bar(void)
 {
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
 
     int row = screen_titlebar_row();
     win = newwin(1, cols, row, 0);
+    if (!win) {
+        // Failed to create title bar window; skip initialization to avoid NULL deref
+        return;
+    }
     wbkgd(win, theme_attrs(THEME_TITLE_TEXT));
     title_bar_console();
     title_bar_set_presence(CONTACT_OFFLINE);
@@ -88,13 +95,18 @@ create_title_bar(void)
 void
 free_title_bar(void)
 {
-    delwin(win);
-    win = NULL;
+    if (win) {
+        delwin(win);
+        win = NULL;
+    }
 }
 
 void
 title_bar_update_virtual(void)
 {
+    if (!win) {
+        return;
+    }
     ProfWin* window = wins_get_current();
     if (window->type != WIN_CONSOLE) {
         if (typing_elapsed) {
@@ -114,7 +126,13 @@ title_bar_update_virtual(void)
 void
 title_bar_resize(void)
 {
+    if (!win) {
+        return;
+    }
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
 
     werase(win);
 
@@ -131,6 +149,9 @@ title_bar_resize(void)
 void
 title_bar_console(void)
 {
+    if (!win) {
+        return;
+    }
     werase(win);
     if (typing_elapsed) {
         g_timer_destroy(typing_elapsed);
@@ -192,6 +213,9 @@ title_bar_set_typing(gboolean is_typing)
 static void
 _title_bar_draw(void)
 {
+    if (!win) {
+        return;
+    }
     int pos;
     int maxrightpos;
     ProfWin* current = wins_get_current();

src/ui/window.c

@@ -80,7 +80,15 @@ win_roster_cols(void)
 {
     int roster_win_percent = prefs_get_roster_size();
     int cols = getmaxx(stdscr);
-    return CEILING((((double)cols) / 100) * roster_win_percent);
+    int width = CEILING((((double)cols) / 100) * roster_win_percent);
+    // Clamp to a sane range to avoid zero/full-width pads
+    if (cols > 1) {
+        if (width < 1) width = 1;
+        if (width >= cols) width = cols - 1;
+    } else {
+        width = 1;
+    }
+    return width;
 }
 
 int
@@ -88,7 +96,15 @@ win_occpuants_cols(void)
 {
     int occupants_win_percent = prefs_get_occupants_size();
     int cols = getmaxx(stdscr);
-    return CEILING((((double)cols) / 100) * occupants_win_percent);
+    int width = CEILING((((double)cols) / 100) * occupants_win_percent);
+    // Clamp to a sane range to avoid zero/full-width pads
+    if (cols > 1) {
+        if (width < 1) width = 1;
+        if (width >= cols) width = cols - 1;
+    } else {
+        width = 1;
+    }
+    return width;
 }
 
 static ProfLayout*
@@ -142,6 +158,7 @@ win_create_console(void)
 ProfWin*
 win_create_chat(const char* const barejid)
 {
+    assert(barejid != NULL);
     ProfChatWin* new_win = malloc(sizeof(ProfChatWin));
     new_win->window.type = WIN_CHAT;
     new_win->window.scroll_state = WIN_SCROLL_INNER;
@@ -173,6 +190,7 @@ win_create_chat(const char* const barejid)
 ProfWin*
 win_create_muc(const char* const roomjid)
 {
+    assert(roomjid != NULL);
     ProfMucWin* new_win = malloc(sizeof(ProfMucWin));
     int cols = getmaxx(stdscr);
 
@@ -230,6 +248,8 @@ win_create_muc(const char* const roomjid)
 ProfWin*
 win_create_config(const char* const roomjid, DataForm* form, ProfConfWinCallback submit, ProfConfWinCallback cancel, const void* userdata)
 {
+    assert(roomjid != NULL);
+    assert(form != NULL);
     ProfConfWin* new_win = malloc(sizeof(ProfConfWin));
     new_win->window.type = WIN_CONFIG;
     new_win->window.scroll_state = WIN_SCROLL_INNER;
@@ -248,6 +268,7 @@ win_create_config(const char* const roomjid, DataForm* form, ProfConfWinCallback
 ProfWin*
 win_create_private(const char* const fulljid)
 {
+    assert(fulljid != NULL);
     ProfPrivateWin* new_win = malloc(sizeof(ProfPrivateWin));
     new_win->window.type = WIN_PRIVATE;
     new_win->window.scroll_state = WIN_SCROLL_INNER;
@@ -278,6 +299,8 @@ win_create_xmlconsole(void)
 ProfWin*
 win_create_plugin(const char* const plugin_name, const char* const tag)
 {
+    assert(plugin_name != NULL);
+    assert(tag != NULL);
     ProfPluginWin* new_win = malloc(sizeof(ProfPluginWin));
     new_win->window.type = WIN_PLUGIN;
     new_win->window.scroll_state = WIN_SCROLL_INNER;
@@ -294,6 +317,7 @@ win_create_plugin(const char* const plugin_name, const char* const tag)
 ProfWin*
 win_create_vcard(vCard* vcard)
 {
+    assert(vcard != NULL);
     ProfVcardWin* new_win = malloc(sizeof(ProfVcardWin));
     new_win->window.type = WIN_VCARD;
     new_win->window.scroll_state = WIN_SCROLL_INNER;
@@ -345,7 +369,7 @@ win_get_title(ProfWin* window)
         const ProfConfWin* confwin = (ProfConfWin*)window;
         assert(confwin->memcheck == PROFCONFWIN_MEMCHECK);
         auto_gchar gchar* mucwin_title = mucwin_generate_title(confwin->roomjid, PREF_TITLEBAR_MUC_TITLE);
-        if (confwin->form->modified) {
+        if (confwin->form && confwin->form->modified) {
             return g_strconcat(mucwin_title, " config *", NULL);
         }
         return g_strconcat(mucwin_title, " config", NULL);
@@ -553,7 +577,25 @@ win_show_subwin(ProfWin* window)
     }
 
     ProfLayoutSplit* layout = (ProfLayoutSplit*)window->layout;
+    // If a subwindow already exists (e.g. repeated call), destroy it to avoid leaks
+    if (layout->subwin) {
+        delwin(layout->subwin);
+        layout->subwin = NULL;
+    }
+
+    // Ensure minimum width to avoid creating a zero-width pad
+    if (subwin_cols <= 0) {
+        subwin_cols = 1;
+    }
+
     layout->subwin = newpad(PAD_SIZE, subwin_cols);
+    if (layout->subwin == NULL) {
+        // Failed to allocate subwindow; keep base window resized to full width
+        log_error("Failed to create subwindow pad (cols=%d)", subwin_cols);
+        wresize(layout->base.win, PAD_SIZE, cols);
+        win_redraw(window);
+        return;
+    }
     wbkgd(layout->subwin, theme_attrs(THEME_TEXT));
     wresize(layout->base.win, PAD_SIZE, cols - subwin_cols);
     win_redraw(window);
@@ -897,6 +939,11 @@ win_refresh_with_subwin(ProfWin* window)
     int row_end = screen_mainwin_row_end();
     ProfLayoutSplit* layout = (ProfLayoutSplit*)window->layout;
 
+    // Safety: if subwindow is not active, nothing to refresh
+    if (layout == NULL || layout->subwin == NULL) {
+        return;
+    }
+
     if (window->type == WIN_MUC) {
         subwin_cols = win_occpuants_cols();
     } else if (window->type == WIN_CONSOLE) {
@@ -2017,7 +2064,14 @@ win_print_loading_history(ProfWin* window)
     gboolean is_buffer_empty = buffer_size(window->layout->buffer) == 0;
 
     if (!is_buffer_empty) {
-        timestamp = buffer_get_entry(window->layout->buffer, 0)->time;
+        ProfBuffEntry* first = buffer_get_entry(window->layout->buffer, 0);
+        if (first && first->time) {
+            timestamp = first->time;
+        } else {
+            // Fallback to current time if entry/time is unavailable
+            timestamp = g_date_time_new_now_local();
+            is_buffer_empty = TRUE; // ensure we unref fallback timestamp below
+        }
     } else {
         timestamp = g_date_time_new_now_local();
     }

src/ui/window_list.c

@@ -407,8 +407,10 @@ wins_get_by_string(const char* str)
         if (barejid) {
             ProfChatWin* chatwin = wins_get_chat(barejid);
             if (chatwin) {
+                free(barejid);
                 return (ProfWin*)chatwin;
             }
+            free(barejid);
         }
     }
 
@@ -603,6 +605,9 @@ wins_new_xmlconsole(void)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_xmlconsole();
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
     autocomplete_add(wins_ac, "xmlconsole");
     autocomplete_add(wins_close_ac, "xmlconsole");
@@ -614,6 +619,9 @@ wins_new_chat(const char* const barejid)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_chat(barejid);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
 
     autocomplete_add(wins_ac, barejid);
@@ -637,6 +645,9 @@ wins_new_muc(const char* const roomjid)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_muc(roomjid);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
     autocomplete_add(wins_ac, roomjid);
     autocomplete_add(wins_close_ac, roomjid);
@@ -651,6 +662,9 @@ wins_new_config(const char* const roomjid, DataForm* form, ProfConfWinCallback s
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_config(roomjid, form, submit, cancel, userdata);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
 
     return newwin;
@@ -661,6 +675,9 @@ wins_new_private(const char* const fulljid)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_private(fulljid);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
     autocomplete_add(wins_ac, fulljid);
     autocomplete_add(wins_close_ac, fulljid);
@@ -675,6 +692,9 @@ wins_new_plugin(const char* const plugin_name, const char* const tag)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_plugin(plugin_name, tag);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
     autocomplete_add(wins_ac, tag);
     autocomplete_add(wins_close_ac, tag);
@@ -686,6 +706,9 @@ wins_new_vcard(vCard* vcard)
 {
     int result = _wins_get_next_available_num(keys);
     ProfWin* newwin = win_create_vcard(vcard);
+    if (!newwin) {
+        return NULL;
+    }
     _wins_htable_insert(windows, GINT_TO_POINTER(result), newwin);
 
     return newwin;