Update bookmarks to reflect permanent redirects upon exiting.

av98.py

@@ -775,6 +775,38 @@ Slow internet connection?  Use 'set timeout' to be more patient.""")
             self.log["ipv6_requests"] += 1
             self.log["ipv6_bytes_recvd"] += size
 
+    def _maintain_bookmarks(self):
+        # Nothing to do if no bookmarks exist!
+        bm_file = os.path.join(self.config_dir, "bookmarks.gmi")
+        if not os.path.exists(bm_file):
+            return
+
+        # Backup bookmark file
+        backup_file = tempfile.NamedTemporaryFile(delete=False)
+        backup_file.close()
+        backup_file = backup_file.name
+        shutil.copyfile(bm_file, backup_file)
+
+        # Attempt maintenance, restore backup if anything fails
+        try:
+            with open(backup_file, "r") as fp_old, open(bm_file, "w") as fp_new:
+                for line in fp_old:
+                    if not line.startswith("=>"):
+                        fp_new.write(line)
+                        continue
+                    old_url = line.split()[1]
+                    url = old_url
+                    while url in self.permanent_redirects:
+                        url = self.permanent_redirects[url]
+                    if url != old_url:
+                        ui_out.debug("Updating old bookmark url {} to {} based on permanent redirect.".format(old_url, url))
+                    fp_new.write(line.replace(old_url, url))
+        except Exception as err:
+            shutil.copyfile(backup_file, bm_file)
+            ui_out.debug(traceback.format_exc())
+        finally:
+            os.unlink(backup_file)
+
     # Cmd implementation follows
 
     def default(self, line):
@@ -1266,6 +1298,8 @@ current gemini browsing session."""
         os.unlink(self.raw_file_buffer)
         os.unlink(self.rendered_file_buffer)
         self.client_cert_manager.cleanup()
+        # Apply permanent redirects to bookmarks
+        self._maintain_bookmarks()
         # Say goodbye
         print()
         print("Thank you for flying AV-98!")