Fix empty reference error. Closes #177

Author: firecat53

keepmenu/__init__.py

@@ -12,6 +12,7 @@
 
 from keepmenu.menu import dmenu_err
 
+
 # Setup logging for debugging. Usage: logger.info(...)
 # import logging
 # logger = logging.getLogger(__name__)
@@ -113,4 +114,25 @@ def reload_config(conf_file = None):  # pylint: disable=too-many-statements,too-
         dmenu_err(f"{' or '.join([shlex.split(i)[0] for i in clips])} needed for clipboard support")
 
 
+def safe_deref(entry, field):
+    """Safely dereference an entry field, handling cases where referenced fields are None.
+
+    When an entry has a field reference (e.g., {REF:U@I:target}) and the target field
+    is None/empty, pykeepass's deref raises a TypeError. This wrapper catches that
+    error and returns an empty string.
+
+    Args:
+        entry: KeePass entry object
+        field: Field name to dereference (e.g., 'username', 'password', 'title')
+
+    Returns:
+        str: Dereferenced field value or empty string if None or error
+
+    """
+    try:
+        return entry.deref(field) or ""
+    except TypeError:
+        # Handle case where referenced field is None
+        return ""
+
 # vim: set et ts=4 sw=4 :

keepmenu/totp.py

@@ -7,6 +7,8 @@
 import time
 from urllib import parse
 
+from keepmenu import safe_deref
+
 
 TOTP_PUBLIC_FIELDS = ('TOTP Settings', 'TimeOtp-Length', 'TimeOtp-Period', 'TimeOtp-Algorithm')
 TOTP_SECRET_FIELDS = ('otp',
@@ -133,7 +135,7 @@ def get_otp_url(kp_entry):
     """
     otp_url = ""
     if hasattr(kp_entry, "otp"):
-        otp_url = kp_entry.deref("otp") or ""
+        otp_url = safe_deref(kp_entry, "otp")
     else:
         otp_url = kp_entry.get_custom_property("otp")
     if otp_url:

keepmenu/type.py

@@ -127,11 +127,11 @@ def type_entry(entry, db_autotype=None):
     libraries.get(library, type_entry_pynput)(entry, tokens)
 
 PLACEHOLDER_AUTOTYPE_TOKENS = {
-    "{TITLE}"   : lambda e: e.deref('title') or "",
-    "{USERNAME}": lambda e: e.deref('username') or "",
-    "{URL}"     : lambda e: e.deref('url') or "",
-    "{PASSWORD}": lambda e: e.deref('password') or "",
-    "{NOTES}"   : lambda e: e.deref('notes') or "",
+    "{TITLE}"   : lambda e: keepmenu.safe_deref(e, 'title'),
+    "{USERNAME}": lambda e: keepmenu.safe_deref(e, 'username'),
+    "{URL}"     : lambda e: keepmenu.safe_deref(e, 'url'),
+    "{PASSWORD}": lambda e: keepmenu.safe_deref(e, 'password'),
+    "{NOTES}"   : lambda e: keepmenu.safe_deref(e, 'notes'),
     "{TOTP}"    : lambda e: gen_otp(get_otp_url(e)),
     "{TIMEOTP}" : lambda e: gen_otp(get_otp_url(e)),
 }

keepmenu/view.py

@@ -20,9 +20,9 @@ def view_all_entries(options, kp_entries, dbname):
     # Have to number each entry to capture duplicates correctly
     kps = str("\n").join([kp_entry_pattern.format(j,
                                                   os.path.join("/".join(i.path[:-1]),
-                                                               i.deref('title') or ""),
-                                                  i.deref('username') or "",
-                                                  i.deref('url') or "",
+                                                               keepmenu.safe_deref(i, 'title')),
+                                                  keepmenu.safe_deref(i, 'username'),
+                                                  keepmenu.safe_deref(i, 'url'),
                                                   na=num_align)
                          for j, i in enumerate(kp_entries)])
     if options:
@@ -50,13 +50,13 @@ def view_entry(kp_entry):
     Returns: dmenu selection
 
     """
-    fields = [os.path.join("/".join(kp_entry.path[:-1]), kp_entry.deref('title') or "")
+    fields = [os.path.join("/".join(kp_entry.path[:-1]), keepmenu.safe_deref(kp_entry, 'title'))
               or "Title: None",
-              kp_entry.deref('username') or "Username: None",
-              '**********' if kp_entry.deref('password') else "Password: None",
+              keepmenu.safe_deref(kp_entry, 'username') or "Username: None",
+              '**********' if keepmenu.safe_deref(kp_entry, 'password') else "Password: None",
               "TOTP: ******" if get_otp_url(kp_entry) else "TOTP: None",
-              kp_entry.deref('url') or "URL: None",
-              "Notes: <Enter to view>" if kp_entry.deref('notes') else "Notes: None",
+              keepmenu.safe_deref(kp_entry, 'url') or "URL: None",
+              "Notes: <Enter to view>" if keepmenu.safe_deref(kp_entry, 'notes') else "Notes: None",
               str(f"Expire time: {kp_entry.expiry_time}")
               if kp_entry.expires is True else "Expiry date: None"]
 
@@ -74,11 +74,11 @@ def view_entry(kp_entry):
 
     sel = dmenu_select(len(fields), inp="\n".join(fields))
     if sel == "Notes: <Enter to view>":
-        sel = view_notes(kp_entry.deref('notes') or "")
+        sel = view_notes(keepmenu.safe_deref(kp_entry, 'notes'))
     elif sel == "Notes: None":
         sel = ""
     elif sel == '**********':
-        sel = kp_entry.deref('password') or ""
+        sel = keepmenu.safe_deref(kp_entry, 'password')
     elif sel == "TOTP: ******":
         sel = gen_otp(get_otp_url(kp_entry))
     elif sel == fields[4] and not keepmenu.CONF.getboolean("database", "type_url", fallback=False):