repo::archive location placeholder expansion fixes, fixes #5826, fixes #5998

- use expanded location for log output
- support placeholder expansion for BORG_REPO env var
- use Location.raw for the unprocessed, not expanded location string

src/borg/helpers/parseformat.py

@@ -382,19 +382,21 @@ class Location:
             raise ValueError('Invalid location format: "%s"' % self.orig)
 
     def parse(self, text, overrides={}):
-        self.orig = text
-        text = replace_placeholders(text, overrides)
+        self.raw = text  # as given by user, might contain placeholders
+        self.orig = text = replace_placeholders(text, overrides)  # after placeholder replacement
         valid = self._parse(text)
         if valid:
             return True
         m = self.env_re.match(text)
         if not m:
             return False
-        repo = os.environ.get('BORG_REPO')
-        if repo is None:
+        repo_raw = os.environ.get('BORG_REPO')
+        if repo_raw is None:
             return False
+        repo = replace_placeholders(repo_raw, overrides)
         valid = self._parse(repo)
         self.archive = m.group('archive')
+        self.raw = repo_raw if not self.archive else repo_raw + self.raw
         self.orig = repo if not self.archive else '%s::%s' % (repo, self.archive)
         return valid
 
@@ -488,14 +490,15 @@ class Location:
                                            path)
 
     def with_timestamp(self, timestamp):
-        return Location(self.orig, overrides={
+        return Location(self.raw, overrides={
             'now': DatetimeWrapper(timestamp.astimezone(None)),
             'utcnow': DatetimeWrapper(timestamp),
         })
 
     def omit_archive(self):
-        loc = Location(self.orig)
+        loc = Location(self.raw)
         loc.archive = None
+        loc.raw = loc.raw.split("::")[0]
         loc.orig = loc.orig.split("::")[0]
         return loc
 

src/borg/testsuite/helpers.py

@@ -235,10 +235,12 @@ class TestLocationWithoutEnv:
             Location('ssh://user@host:/path')
 
     def test_omit_archive(self):
-        loc = Location('ssh://user@host:1234/some/path::archive')
+        from borg.platform import hostname
+        loc = Location('ssh://user@host:1234/repos/{hostname}::archive')
         loc_without_archive = loc.omit_archive()
         assert loc_without_archive.archive is None
-        assert loc_without_archive.orig == "ssh://user@host:1234/some/path"
+        assert loc_without_archive.raw == "ssh://user@host:1234/repos/{hostname}"
+        assert loc_without_archive.orig == "ssh://user@host:1234/repos/%s" % hostname
 
 
 class TestLocationWithEnv:
@@ -251,6 +253,16 @@ class TestLocationWithEnv:
         assert repr(Location()) == \
                "Location(proto='ssh', user='user', host='host', port=1234, path='/some/path', archive=None)"
 
+    def test_ssh_placeholder(self, monkeypatch):
+        from borg.platform import hostname
+        monkeypatch.setenv('BORG_REPO', 'ssh://user@host:1234/{hostname}')
+        assert repr(Location('::archive')) == \
+            "Location(proto='ssh', user='user', host='host', port=1234, path='/{}', archive='archive')".format(hostname)
+        assert repr(Location('::')) == \
+            "Location(proto='ssh', user='user', host='host', port=1234, path='/{}', archive=None)".format(hostname)
+        assert repr(Location()) == \
+            "Location(proto='ssh', user='user', host='host', port=1234, path='/{}', archive=None)".format(hostname)
+
     def test_file(self, monkeypatch):
         monkeypatch.setenv('BORG_REPO', 'file:///some/path')
         assert repr(Location('::archive')) == \