Change the Gopher index filename to gophermap

This seems to be the most common convention among gopher servers (e.g.
Gophernicus, go-gopher).

Added a script to migrate the cache to the new format. Alternatively the
following command can be used for migration in a POSIX system:

find ~/.cache/offpunk/gopher/ -type f -name 'index.txt' -exec sh -c 'mv {} "$(dirname {})/gophermap"' \;

CHANGELOG

@@ -2,6 +2,7 @@
 
 ## 1.10 - unreleased
 - IMPORTANT : new optional dependency : python-chardet
+- IMPORTANT : Gopher directory index filename changed from "index.txt" to "gophermap". To update the cache to the new format run the `migrate-offpunk-cache` script (Sotiris Papatheodorou)
 - "set accept_bad_ssl_certificates True" now also used for Gemini expired certificates
 - Add missing chardet module (Sotiris Papatheodorou)
 - Fix merging dictionaries with common keys (Sotiris Papatheodorou)

migrate-offpunk-cache

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+# SPDX-FileCopyrightText: 2023 Sotiris Papatheodorou
+# SPDX-License-Identifier: BSD-2-Clause
+
+"""
+A script to migrate the offpunk cache to the newest version.
+
+For each new version of offpunk that requires changes to the cache a migration
+function should be written. The name of the function should have the format
+v<major-version>_<minor-version>_<patch-version> and it should accept the
+offpunk cache directory as a string. The function should perform a migration
+from the immediately previous cache format. All migration functions must be
+called at the end of this script from oldest to newest.
+"""
+
+import argparse
+import os
+import os.path
+
+
+def v1_10_0(cache_dir: str) -> None:
+    """
+    Rename index.txt to gophermap in the Gopher protocol cache.
+    """
+    for root, _, files in os.walk(os.path.join(cache_dir, 'gopher')):
+        for f in files:
+            if f == 'index.txt':
+                src = os.path.join(root, f)
+                dst = os.path.join(root, 'gophermap')
+                os.rename(src, dst)
+
+
+if __name__ == '__main__':
+    # Compute the default offpunk cache directory.
+    xdg_cache_home = os.environ.get('XDG_CACHE_HOME')
+    if xdg_cache_home:
+        default_cache_dir = os.path.join(xdg_cache_home, 'offpunk')
+    else:
+        default_cache_dir = os.path.join(os.path.expanduser('~'), '.cache/offpunk')
+    # Parse command line arguments.
+    parser = argparse.ArgumentParser(
+        description='Migrate the offpunk cache to a newer version.')
+    parser.add_argument('cache_dir', metavar='CACHE_DIR', nargs='?',
+        default=default_cache_dir, help='the path to the cache')
+    args = parser.parse_args()
+    # Run the cache migration functions from the oldest to the newest version.
+    v1_10_0(args.cache_dir)

offpunk.py

@@ -1439,8 +1439,10 @@ class GeminiItem():
             # finish by "/". Else, the cache will create a file, not a folder.
             if self.scheme.startswith("http"):
                 index = "index.html"
-            elif self.scheme in ["gopher", "finger"]:
+            elif self.scheme == "finger":
                 index = "index.txt"
+            elif self.scheme == "gopher":
+                index = "gophermap"
             else:
                 index = "index.gmi"
             if self.path == "" or os.path.isdir(self._cache_path):