fix(ui,db): harden NULL handling, fix CWE-134, optimize iterations

security(CWE-134): fix format string injections + add CI check
fix(ui): subwindow lifecycle, newwin/newpad guards, fallback timestamps
fix(db): sqlite cleanup on failures, sqlite3_close_v2
fix(xmpp): queued_messages loop, barejid leak
perf(core): g_hash_table_iter_init instead of g_hash_table_get_keys
refactor(ui): CLAMP macro in _check_subwin_width
test: XEP-0012 and XEP-0045 functional tests

Author: jabber.developer2
Closes #58, #85

src/database.c

@@ -65,6 +65,38 @@ static gboolean _check_available_space_for_db_migration(char* path_to_db);
 
 static const int latest_version = 2;
 
+// Helper: close DB handle (if any), warn on busy, and shutdown SQLite
+static void
+_db_teardown(const char* ctx)
+{
+    if (g_chatlog_database) {
+        int rc = sqlite3_close_v2(g_chatlog_database);
+        if (rc != SQLITE_OK) {
+            log_warning("sqlite3_close_v2 in %s returned %d; database may still have active statements.",
+                        ctx ? ctx : "db_teardown", rc);
+        }
+        g_chatlog_database = NULL;
+    }
+    // Safe to call unconditionally; no-op if not initialized.
+    // See: https://www.sqlite.org/c3ref/initialize.html
+    sqlite3_shutdown();
+}
+
+// Helper: prepare a statement and log a contextual error on failure
+static gboolean
+_db_prepare_ctx(const char* query, sqlite3_stmt** stmt, const char* ctx)
+{
+    int rc = sqlite3_prepare_v2(g_chatlog_database, query, -1, stmt, NULL);
+    if (rc != SQLITE_OK) {
+        log_error("SQLite error in %s: (error code: %d) %s",
+                  ctx ? ctx : "sqlite3_prepare_v2",
+                  rc,
+                  sqlite3_errmsg(g_chatlog_database));
+        return FALSE;
+    }
+    return TRUE;
+}
+
 static char*
 _db_strdup(const char* str)
 {
@@ -98,17 +130,19 @@ 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);
+        _db_teardown("log_database_init(open)");
         return FALSE;
     }
 
-    char* err_msg;
+    char* err_msg = NULL;
 
     int db_version = _get_db_version();
     if (db_version == latest_version) {
@@ -216,6 +250,7 @@ out:
     } else {
         log_error("Unknown SQLite error in log_database_init().");
     }
+    _db_teardown("log_database_init(out)");
     return FALSE;
 }
 
@@ -223,11 +258,7 @@ void
 log_database_close(void)
 {
     log_debug("log_database_close() called");
-    if (g_chatlog_database) {
-        sqlite3_close(g_chatlog_database);
-        sqlite3_shutdown();
-        g_chatlog_database = NULL;
-    }
+    _db_teardown("log_database_close");
 }
 
 void
@@ -281,8 +312,15 @@ 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 +331,19 @@ 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;
+    if (!_db_prepare_ctx(query, &stmt, "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 +353,11 @@ 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;
 }
 
@@ -357,9 +402,7 @@ log_database_get_previous_chat(const gchar* const contact_barejid, const gchar*
         return DB_RESPONSE_ERROR;
     }
 
-    int rc = sqlite3_prepare_v2(g_chatlog_database, query, -1, &stmt, NULL);
-    if (rc != SQLITE_OK) {
-        log_error("SQLite error in log_database_get_previous_chat(): (error code: %d) %s", rc, sqlite3_errmsg(g_chatlog_database));
+    if (!_db_prepare_ctx(query, &stmt, "log_database_get_previous_chat()")) {
         return DB_RESPONSE_ERROR;
     }
 
@@ -503,9 +546,7 @@ _add_to_db(ProfMessage* message, char* type, const Jid* const from_jid, const Ji
         }
 
         sqlite3_stmt* lmc_stmt = NULL;
-
-        if (SQLITE_OK != sqlite3_prepare_v2(g_chatlog_database, replace_check_query, -1, &lmc_stmt, NULL)) {
-            log_error("SQLite error in _add_to_db() on selecting original message: %s", sqlite3_errmsg(g_chatlog_database));
+        if (!_db_prepare_ctx(replace_check_query, &lmc_stmt, "_add_to_db(replace_check)")) {
             return;
         }
 
@@ -542,8 +583,7 @@ _add_to_db(ProfMessage* message, char* type, const Jid* const from_jid, const Ji
         }
 
         sqlite3_stmt* stmt;
-
-        if (SQLITE_OK == sqlite3_prepare_v2(g_chatlog_database, duplicate_check_query, -1, &stmt, NULL)) {
+        if (_db_prepare_ctx(duplicate_check_query, &stmt, "_add_to_db(duplicate_check)")) {
             if (sqlite3_step(stmt) == SQLITE_ROW) {
                 log_error("Duplicate stanza-id found for the message. stanza_id: %s; archive_id: %s; sender: %s; content: %s", message->id, message->stanzaid, from_jid->barejid, message->plain);
                 cons_show_error("Got a message with duplicate (server-generated) stanza-id from %s.", from_jid->fulljid);
@@ -599,8 +639,7 @@ _get_db_version(void)
     int current_version = -1;
     const char* query = "SELECT `version` FROM `DbVersion` LIMIT 1";
     sqlite3_stmt* statement;
-
-    if (sqlite3_prepare_v2(g_chatlog_database, query, -1, &statement, NULL) == SQLITE_OK) {
+    if (_db_prepare_ctx(query, &statement, "_get_db_version()")) {
         if (sqlite3_step(statement) == SQLITE_ROW) {
             current_version = sqlite3_column_int(statement, 0);
         }