rclone does not address a file by the bytes os.OpenFile wrote. Names handed to
an Fs go through the backend encoder and names listed back are re-encoded to
the standard set, neither of which the write path performs. A filename holding
one of the rewritten characters was therefore stored under one string and
looked up under another: confirmed against the local backend, where a written
"a‛b.jpg" reports object not found and a written "a\nb.jpg" lists back as
"a␊b.jpg". That is the same two-derivation divergence this program was written
to remove, with rclone's encoder standing where filenamify used to. Such names
are rejected, not encoded, for the same reason every other name is.
The length limit ignored the ".part" suffix that is opened first, so a name
just inside NAME_MAX passed the check and then failed to open on every pass,
stalling the walk on that message forever. The suffix now lives beside the
limit that has to account for it.
filter.NewFilter(nil) does not build a neutral filter; it copies the package
global, which rclone has already filled from RCLONE_*. Indexing inherited the
operator's environment, so a stray RCLONE_MIN_SIZE emptied the index and
re-downloaded the archive. Every narrowing field is now set explicitly and the
result is asserted inactive. A subprocess test covers it, since the env is read
at package init and t.Setenv is too late to observe anything.
An ErrorDirNotFound from a subdirectory was also treated as an empty
destination, returning a partial index as authoritative.
t.me/c/<id> and t.me/s/<name> were passed through whole, and gotd reads the
first path component as the username — resolving "c" or "s", which is a
confusing failure at best and someone else's chat at worst, since
one-character usernames exist. Both now yield the chat, and t.me/s/<name>/<id>
is refused like any other message link. Two tests asserted the old behaviour.
core's dcpool.Takeout deadlocks when takeout init fails: it holds the pool
mutex and recovers by calling Client, which takes the same non-reentrant
mutex. Telegram returns TAKEOUT_INIT_DELAY for a takeout started recently and
takeout is on by default, so two runs in succession hang the process with no
output and no response to cancellation. The session is established once here
instead, falling back to a plain client, and the pool's own Takeout is never
called.
Second slice: the read path, and the fix for the bug that motivated the
rewrite.
The shell pipeline derived a filename twice. `tdl chat export` wrote the raw
Telegram name into a JSON, while `tdl dl` rendered it through a template whose
default pipes it through filenamify, which rewrites reserved characters and
collapses runs of '!'. A message whose name contained '!!' was therefore looked
up under one name and stored under another; the verifier never found it and
re-fetched it on every pass. Here a single function produces the name, and the
string it returns is used both to test for presence and to write the file, so
the two cannot disagree.
Names are stored exactly as Telegram reports them rather than reproducing
filenamify. That is a deliberate break from what the old pipeline wrote: a file
it stored under a rewritten name is not recognised and will be fetched again.
For the one chat archived so far that is a single file out of 18155, already
removed. Because names are verbatim they are not path-safe, so the code that
turns one into a path must enforce containment.
Walk yields a sequence rather than taking a callback, since the downloader
consumes a pull iterator and range-over-func converts either way without anyone
owning a goroutine. It pages newest first, where the old pipeline went oldest
first, which changes what an interrupted run leaves behind.
Message links are refused rather than guessed at, across every host Telegram
uses and the tg:// forms that carry the message id in a query parameter. A
private channel link and a public message link have the same shape, so the two
are told apart by parsing rather than by pattern.
Verified against the live chat: 18155 media messages, matching the shell
verifier, and every one of the 15548 objects already on the remote is found
under a derived name.