From 60da899bd9e490a0297ed67ee704b8243dc3c360 Mon Sep 17 00:00:00 2001
From: "jabber.developer2" <jabber.developer2@jabber.space>
Date: Tue, 28 Apr 2026 17:19:20 +0300
Subject: [PATCH] fix: address open PR #105 review comments (leaks + null
 safety)

- ui/window.c win_show_subwin (#1144): unconditional newpad without
  freeing the previous pad leaks the ncurses subwin if the function
  is invoked twice without an intervening win_hide_subwin. Added a
  delwin guard.
- omemo/omemo.c omemo_on_disconnect (#1126): hash tables and
  libsignal handles are destroyed unconditionally even when a full
  init never ran (e.g. shutdown after a failed load), and neither
  g_hash_table_destroy nor signal_*_destroy are documented as
  NULL-safe. NULL-check each handle before tearing it down.
- xmpp/roster_list.c (#1140 / #1141 / #1160): null the caller's
  pointer immediately after resource_destroy() so a stale reference
  cannot trigger a double-free; resource_destroy itself only zeroes
  the struct fields it owns and cannot reach back to the caller.
---
 src/omemo/omemo.c      | 23 ++++++++++++++++++-----
 src/ui/window.c        |  5 +++++
 src/xmpp/roster_list.c |  2 ++
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/omemo/omemo.c b/src/omemo/omemo.c
index 657266c9..b018158b 100644
--- a/src/omemo/omemo.c
+++ b/src/omemo/omemo.c
@@ -281,11 +281,24 @@ omemo_on_disconnect(void)
     }
 
     free_keyfile(&omemo_ctx.identity);
-    g_hash_table_destroy(omemo_ctx.known_devices);
-    g_hash_table_destroy(omemo_ctx.device_list_handler);
-    g_hash_table_destroy(omemo_ctx.device_list);
-    signal_protocol_store_context_destroy(omemo_ctx.store);
-    signal_context_destroy(omemo_ctx.signal);
+    /* These can be NULL when omemo_on_disconnect runs before a full
+     * init has populated them; g_hash_table_destroy and the libsignal
+     * destructors are not documented to be NULL-safe. */
+    if (omemo_ctx.known_devices) {
+        g_hash_table_destroy(omemo_ctx.known_devices);
+    }
+    if (omemo_ctx.device_list_handler) {
+        g_hash_table_destroy(omemo_ctx.device_list_handler);
+    }
+    if (omemo_ctx.device_list) {
+        g_hash_table_destroy(omemo_ctx.device_list);
+    }
+    if (omemo_ctx.store) {
+        signal_protocol_store_context_destroy(omemo_ctx.store);
+    }
+    if (omemo_ctx.signal) {
+        signal_context_destroy(omemo_ctx.signal);
+    }
     memset(&omemo_ctx, 0, sizeof(omemo_ctx));
 
     wins_omemo_trust_changed(NULL);
diff --git a/src/ui/window.c b/src/ui/window.c
index 6fb46ac1..7624c22c 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -577,6 +577,11 @@ win_show_subwin(ProfWin* window)
     }
 
     ProfLayoutSplit* layout = (ProfLayoutSplit*)window->layout;
+    /* Free a previous pad if win_show_subwin was called twice in a row
+     * without an intervening win_hide_subwin. */
+    if (layout->subwin) {
+        delwin(layout->subwin);
+    }
     layout->subwin = newpad(PAD_MIN_HEIGHT, subwin_cols);
     wbkgd(layout->subwin, theme_attrs(THEME_TEXT));
     wresize(layout->base.win, PAD_MIN_HEIGHT, cols - subwin_cols);
diff --git a/src/xmpp/roster_list.c b/src/xmpp/roster_list.c
index 47be2f19..0a9ea14d 100644
--- a/src/xmpp/roster_list.c
+++ b/src/xmpp/roster_list.c
@@ -88,6 +88,7 @@ _pendingPresence_free(ProfPendingPresence* presence)
         g_date_time_unref(presence->last_activity);
     free(presence->barejid);
     resource_destroy(presence->resource);
+    presence->resource = NULL;
     free(presence);
 }
 
@@ -136,6 +137,7 @@ roster_update_presence(const char* const barejid, Resource* resource, GDateTime*
     if (contact == NULL) {
         /* Don't lose resource when there is no owner. */
         resource_destroy(resource);
+        resource = NULL;
         return FALSE;
     }
     if (!_datetimes_equal(p_contact_last_activity(contact), last_activity)) {