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go/api
Brad Fitzpatrick 3058d38632 strings: fix two Builder bugs allowing mutation of strings, remove ReadFrom
The Builder's ReadFrom method allows the underlying unsafe slice to
escape, and for callers to subsequently modify memory that had been
unsafely converted into an immutable string.

In the original proposal for Builder (#18990), I'd noted there should
be no Read methods:

> There would be no Reset or Bytes or Truncate or Read methods.
> Nothing that could mutate the []byte once it was unsafely converted
> to a string.

And in my prototype (https://golang.org/cl/37767), I handled ReadFrom
properly, but when https://golang.org/cl/74931 arrived, I missed that
it had a ReadFrom method and approved it.

Because we're so close to the Go 1.10 release, just remove the
ReadFrom method rather than think about possible fixes. It has
marginal utility in a Builder anyway.

Also, fix a separate bug that also allowed mutation of a slice's
backing array after it had been converted into a slice by disallowing
copies of the Builder by value.

Updates #18990
Fixes #23083
Fixes #23084

Change-Id: Id1f860f8a4f5f88b32213cf85108ebc609acb95f
Reviewed-on: https://go-review.googlesource.com/83255
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-11 19:20:05 +00:00
..
except.txt unicode: update to Unicode 10.0.0 2017-10-24 12:42:35 +00:00
go1.1.txt go/constant: switch to floating-point representation when fractions become too large 2015-12-14 23:42:01 +00:00
go1.2.txt
go1.3.txt
go1.4.txt
go1.5.txt api: update go1.5.txt 2015-07-30 21:14:09 +00:00
go1.6.txt go/types: rename Importer2 to ImporterFrom 2016-01-13 23:40:13 +00:00
go1.7.txt unicode: upgrade to version 9.0.0 2016-06-28 15:08:11 +00:00
go1.8.txt Revert "cmd/go: note when some Go files were ignored on no-Go-files errors" 2016-12-21 05:25:57 +00:00
go1.9.txt doc, api: add syscall.SysProcAttr.AmbientCaps change to 1.9 notes, API 2017-06-29 03:29:46 +00:00
go1.10.txt strings: fix two Builder bugs allowing mutation of strings, remove ReadFrom 2017-12-11 19:20:05 +00:00
go1.txt
next.txt api: promote next to go1.10 2017-12-07 15:44:34 +00:00
README api: fix typo in README 2015-12-19 07:15:39 +00:00

Files in this directory are data for Go's API checker ("go tool api", in src/cmd/api).

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
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except.txt lists features that may disappear without breaking true
compatibility.

next.txt is the only file intended to be mutated. It's a list of
features that may be added to the next version. It only affects
warning output from the go api tool.