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/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();
     }