…xps in Parse

The regexp code assumes it can recurse over the structure of
a regexp safely. Go's growable stacks make that reasonable
for all plausible regexps, but implausible ones can reach the
“infinite recursion?” stack limit.

This CL limits the depth of any parsed regexp to 1000.
That is, the depth of the parse tree is required to be ≤ 1000.
Regexps that require deeper parse trees will return ErrInternalError.
A future CL will change the error to ErrInvalidDepth,
but using ErrInternalError for now avoids introducing new API
in point releases when this is backported.

Fixes #51112.
Fixes #51117.

Change-Id: I97d2cd82195946eb43a4ea8561f5b95f91fb14c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/384616
Trust: Russ Cox <[email protected]>
Run-TryBot: Russ Cox <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Reviewed-on: https://go-review.googlesource.com/c/go/+/384855

…1232 bytes

The existing value of 512 bytes as is specified by RFC 1035.
However, the WSL resolver reportedly sends larger packets without
setting the truncation bit, which breaks using the Go resolver.
For 1.18 and backports, just increase the accepted packet size.
This is what GNU glibc does (they use 65536 bytes).

For 1.19 we plan to use EDNS to set the accepted packet size.
That will give us more time to test whether that causes any problems.

No test because I'm not sure how to write one and it wouldn't really
be useful anyhow.

For #6464
For #21160
For #44135
For #51127
For #51153
Fixes #51161

Change-Id: I0243f274a06e010ebb714e138a65386086aecf17
Reviewed-on: https://go-review.googlesource.com/c/go/+/386015
Trust: Ian Lance Taylor <[email protected]>
Run-TryBot: Ian Lance Taylor <[email protected]>
Reviewed-by: Damien Neil <[email protected]>
Reviewed-by: Matthew Dempsky <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
(cherry picked from commit 6e82ff8)
Reviewed-on: https://go-review.googlesource.com/c/go/+/386034
Reviewed-by: Dmitri Shuralyov <[email protected]>

There was an off-by-one error in the time histogram buckets calculation
that caused the linear sub-buckets distances to be off by 2x.

The fix was trivial, but in writing tests I realized there was a much
simpler way to express the calculation for the histogram buckets, and
took the opportunity to do that here. The new bucket calculation also
fixes the bug.

For #50732.
Fixes #50733.

Change-Id: Idae89986de1c415ee4e148f778e0e101ca003ade
Reviewed-on: https://go-review.googlesource.com/c/go/+/380094
Reviewed-by: Michael Pratt <[email protected]>
Reviewed-by: Emmanuel Odeke <[email protected]>
Trust: Michael Knyszek <[email protected]>
Run-TryBot: Michael Knyszek <[email protected]>
(cherry picked from commit 2e9dcb5)
Reviewed-on: https://go-review.googlesource.com/c/go/+/384620

…ce on RISCV64

Pointer comparison is lowered to the following on RISCV64

(EqPtr x y) => (SEQZ (SUB <x.Type> x y))

The difference of two pointers (the SUB) should not be pointer
type. Otherwise it can cause the GC to find a bad pointer.

Updates #51101.
Fixes #51198.

Change-Id: I7e73c2155c36ff403c032981a9aa9cccbfdf0f64
Reviewed-on: https://go-review.googlesource.com/c/go/+/385655
Trust: Cherry Mui <[email protected]>
Run-TryBot: Cherry Mui <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
(cherry picked from commit 1ed30ca)
Reviewed-on: https://go-review.googlesource.com/c/go/+/386475

… a go.mod file exists in a subdirectory for that version

Previous versions of the 'go' command would reject a pseudo-version
passed to 'go get' if that pseudo-version had a mismatched major
version and lacked a "+incompatible" suffix. However, they would
erroneously accept a version *with* a "+incompatible" suffix even if
the repo contained a vN/go.mod file for the same major version, and
would generate a "+incompatible" pseudo-version or version if the user
requested a tag, branch, or commit hash.

This change uniformly rejects "vN.…" without "+incompatible", and also
avoids resolving to "vN.…+incompatible", when vN/go.mod exists.
To maintain compatibility with existing go.mod files, it still accepts
"vN.…+incompatible" if the version is requested explicitly as such
and the repo root lacks a go.mod file.

Fixes #51331
Updates #51324
Updates #36438

Change-Id: I2b16150c73fc2abe4d0a1cd34cb1600635db7139
Reviewed-on: https://go-review.googlesource.com/c/go/+/387675
Trust: Bryan Mills <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
(cherry picked from commit 5a9fc94)
Reviewed-on: https://go-review.googlesource.com/c/go/+/387923
Run-TryBot: Bryan Mills <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Change-Id: Ibf99abee4463badcd5f4ee86d2503855bf78c91b
Reviewed-on: https://go-review.googlesource.com/c/go/+/389737
Trust: Carlos Amedee <[email protected]>
Run-TryBot: Carlos Amedee <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Alex Rakoczy <[email protected]>