[dev.typeparams] all: merge master (46fd547) into dev.typeparams

Conflicts:

- src/go/types/check_test.go

  CL 324730 on dev.typeparams changed the directory paths in TestCheck,
  TestExamples, and TestFixedbugs and renamed checkFiles to testFiles;
  whereas CL 337529 on master added a new test case just above them and
  that used checkFiles.

Merge List:

+ 2021-08-12 46fd547d89 internal/goversion: update Version to 1.18
+ 2021-08-12 5805efc78e doc/go1.17: remove draft notice
+ 2021-08-12 39634e7dae CONTRIBUTORS: update for the Go 1.17 release
+ 2021-08-12 095bb790e1 os/exec: re-enable LookPathTest/16
+ 2021-08-11 dea23e9ca8 src/make.*: make --no-clean flag a no-op that prints a warning
+ 2021-08-11 d4c0ed26ac doc/go1.17: linker passes -I to extld as -Wl,--dynamic-linker
+ 2021-08-10 1f9c9d8530 doc: use "high address/low address" instead of "top/bottom"
+ 2021-08-09 f1dce319ff cmd/go: with -mod=vendor, don't panic if there are duplicate requirements
+ 2021-08-09 7aeaad5c86 runtime/cgo: when using msan explicitly unpoison cgoCallers
+ 2021-08-08 507cc341ec doc: add example for conversion from slice expressions to array ptr
+ 2021-08-07 891547e2d4 doc/go1.17: fix a typo introduced in CL 335135
+ 2021-08-06 8eaf4d16bc make.bash: do not overwrite GO_LDSO if already set
+ 2021-08-06 63b968f4f8 doc/go1.17: clarify Modules changes
+ 2021-08-06 70546f6404 runtime: allow arm64 SEH to be called if illegal instruction
+ 2021-08-05 fd45e267c2 runtime: warn that KeepAlive is not an unsafe.Pointer workaround
+ 2021-08-04 6e738868a7 net/http: speed up and deflake TestCancelRequestWhenSharingConnection
+ 2021-08-02 8a7ee4c51e io/fs: don't use absolute path in DirEntry.Name doc
+ 2021-07-31 b8ca6e59ed all: gofmt
+ 2021-07-30 b7a85e0003 net/http/httputil: close incoming ReverseProxy request body
+ 2021-07-29 70fd4e47d7 runtime: avoid possible preemption when returning from Go to C
+ 2021-07-28 9eee0ed439 cmd/go: fix go.mod file name printed in error messages for replacements
+ 2021-07-28 b39e0f461c runtime: don't crash on nil pointers in checkptrAlignment
+ 2021-07-27 7cd10c1149 cmd/go: use .mod instead of .zip to determine if version has go.mod file
+ 2021-07-27 c8cf0f74e4 cmd/go: add missing flag in UsageLine
+ 2021-07-27 7ba8e796c9 testing: clarify T.Name returns a distinct name of the running test
+ 2021-07-27 33ff155970 go/types: preserve untyped constants on the RHS of a shift expression
+ 2021-07-26 840e583ff3 runtime: correct variable name in comment
+ 2021-07-26 bfbb288574 runtime: remove adjustTimers counter
+ 2021-07-26 9c81fd53b3 cmd/vet: add missing copyright header

Change-Id: Ia80604d24c6f4205265683024e3100769cf32065

1 files changed, 34 insertions, 0 deletions

diff --git a/src/cmd/go/testdata/script/mod_update_sum_readonly.txt b/src/cmd/go/testdata/script/mod_update_sum_readonly.txt
new file mode 100644
index 0000000000..41f12e4084
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_update_sum_readonly.txt
@@ -0,0 +1,34 @@
+# When finding the latest version of a module, we should not download version
+# contents. Previously, we downloaded .zip files to determine whether a real
+# .mod file was present in order to decide whether +incompatible versions
+# could be "latest".
+#
+# Verifies #47377.
+
+# rsc.io/breaker has two versions, neither of which has a .mod file.
+go list -m -versions rsc.io/breaker
+stdout '^rsc.io/breaker v1.0.0 v2.0.0\+incompatible$'
+go mod download rsc.io/breaker@v1.0.0
+! grep '^go' $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v1.0.0.mod
+go mod download rsc.io/breaker@v2.0.0+incompatible
+! grep '^go' $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v2.0.0+incompatible.mod
+
+# Delete downloaded .zip files.
+go clean -modcache
+
+# Check for updates.
+go list -m -u rsc.io/breaker
+stdout '^rsc.io/breaker v1.0.0 \[v2.0.0\+incompatible\]$'
+
+# We should not have downloaded zips.
+! exists $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v1.0.0.zip
+! exists $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v2.0.0+incompatible.zip
+
+-- go.mod --
+module m
+
+go 1.16
+
+require rsc.io/breaker v1.0.0
+-- go.sum --
+rsc.io/breaker v1.0.0/go.mod h1:s5yxDXvD88U1/ESC23I2FK3Lkv4YIKaB1ij/Hbm805g=