Julian Soreavis 1e28d9f580 encoding/base64, encoding/base32: panic when encoded length overflows int
EncodedLen computes the encoded length with int arithmetic that can
wrap for very large n, returning a negative or wrapped value. Callers
that size an allocation from the result (EncodeToString, AppendEncode)
then panic with no indication of the cause, or allocate an undersized
buffer. CL 510635 and CL 512200 raised the overflow threshold of the
unpadded branches but did not eliminate it, and the padded branches
were unchanged: on 32-bit platforms
base64.StdEncoding.EncodedLen(1610612736) still returns -2147483648.

Make EncodedLen panic when the encoded length does not fit in an int,
document the panic, and document the largest n that is guaranteed not
to panic. DecodedLen needs no change: its result is at most n and
cannot overflow.

Fixes #20235

Change-Id: I963a55062a790017b42f49fc3a9178fc3bb024ef
GitHub-Last-Rev: 2a7abbb35f7f5e3a2b74c379c29464e01e2206f5
GitHub-Pull-Request: golang/go#80373
Reviewed-on: https://go-review.googlesource.com/c/go/+/799800
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2026-07-15 14:30:36 -07:00
..

Release Notes

The initial and next subdirectories of this directory are for release notes.

For developers

Release notes should be added to next by editing existing files or creating new files. Do not add RELNOTE=yes comments in CLs. Instead, add a file to the CL (or ask the author to do so).

At the end of the development cycle, the files will be merged by being concatenated in sorted order by pathname. Files in the directory matching the glob "*stdlib/*minor" are treated specially. They should be in subdirectories corresponding to standard library package paths, and headings for those package paths will be generated automatically.

Files in this repo's api/next directory must have corresponding files in doc/next/*stdlib/*minor. The files should be in the subdirectory for the package with the new API, and should be named after the issue number of the API proposal. For example, if the directory 6-stdlib/99-minor is present, then an api/next file with the line

pkg net/http, function F #12345

should have a corresponding file named doc/next/6-stdlib/99-minor/net/http/12345.md. At a minimum, that file should contain either a full sentence or a TODO, ideally referring to a person with the responsibility to complete the note.

If your CL addresses an accepted proposal, mention the proposal issue number in your release note in the form /issue/NUMBER. A link to the issue in the text will have this form (see below). If you don't want to mention the issue in the text, add it as a comment:

<!-- go.dev/issue/12345 -->

If an accepted proposal is mentioned in a CL but not in the release notes, it will be flagged as a TODO by the automated tooling. That is true even for proposals that add API.

Use the following forms in your markdown:

[http.Request]                     # symbol documentation; auto-linked as in Go doc strings
[Request]                          # short form, for symbols in the package being documented
[net/http]                         # package link
[#12345](/issue/12345)             # GitHub issues
[CL 6789](/cl/6789)                # Gerrit changelists

To preview next content in merged form using a local instance of the website, run:

go run golang.org/x/website/cmd/golangorg@latest -goroot=..

Then open http://localhost:6060/doc/next. Refresh the page to see your latest edits.

For the release team

The relnote tool, at golang.org/x/build/cmd/relnote, operates on the files in doc/next.

As a release cycle nears completion, run relnote todo to get a list of unfinished release note work.

To prepare the release notes for a release, run relnote generate. That will merge the .md files in next into a single file. Atomically (as close to it as possible) add that file to _content/doc directory of the website repository and remove the doc/next directory in this repository.

To begin the next release development cycle, populate the contents of next with those of initial. From the repo root:

> cd doc
> cp -R initial/ next

Then edit next/1-intro.md to refer to the next version.