[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, 18 insertions, 21 deletions

diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index a8cbd9fe16..45f724d5e3 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -449,13 +449,22 @@ func loadModFile(ctx context.Context) (rs *Requirements, needCommit bool) {
 	}
 
 	setDefaultBuildMod() // possibly enable automatic vendoring
-	rs = requirementsFromModFile(ctx)
-
+	rs = requirementsFromModFile()
 	if cfg.BuildMod == "vendor" {
 		readVendorList()
 		checkVendorConsistency()
 		rs.initVendor(vendorList)
 	}
+	if rs.hasRedundantRoot() {
+		// If any module path appears more than once in the roots, we know that the
+		// go.mod file needs to be updated even though we have not yet loaded any
+		// transitive dependencies.
+		rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
+		if err != nil {
+			base.Fatalf("go: %v", err)
+		}
+	}
+
 	if index.goVersionV == "" {
 		// TODO(#45551): Do something more principled instead of checking
 		// cfg.CmdName directly here.
@@ -530,7 +539,12 @@ func CreateModFile(ctx context.Context, modPath string) {
 		base.Fatalf("go: %v", err)
 	}
 
-	commitRequirements(ctx, modFileGoVersion(), requirementsFromModFile(ctx))
+	rs := requirementsFromModFile()
+	rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
+	if err != nil {
+		base.Fatalf("go: %v", err)
+	}
+	commitRequirements(ctx, modFileGoVersion(), rs)
 
 	// Suggest running 'go mod tidy' unless the project is empty. Even if we
 	// imported all the correct requirements above, we're probably missing
@@ -641,9 +655,8 @@ func initTarget(m module.Version) {
 
 // requirementsFromModFile returns the set of non-excluded requirements from
 // the global modFile.
-func requirementsFromModFile(ctx context.Context) *Requirements {
+func requirementsFromModFile() *Requirements {
 	roots := make([]module.Version, 0, len(modFile.Require))
-	mPathCount := map[string]int{Target.Path: 1}
 	direct := map[string]bool{}
 	for _, r := range modFile.Require {
 		if index != nil && index.exclude[r.Mod] {
@@ -656,28 +669,12 @@ func requirementsFromModFile(ctx context.Context) *Requirements {
 		}
 
 		roots = append(roots, r.Mod)
-		mPathCount[r.Mod.Path]++
 		if !r.Indirect {
 			direct[r.Mod.Path] = true
 		}
 	}
 	module.Sort(roots)
 	rs := newRequirements(modDepthFromGoVersion(modFileGoVersion()), roots, direct)
-
-	// If any module path appears more than once in the roots, we know that the
-	// go.mod file needs to be updated even though we have not yet loaded any
-	// transitive dependencies.
-	for _, n := range mPathCount {
-		if n > 1 {
-			var err error
-			rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
-			if err != nil {
-				base.Fatalf("go: %v", err)
-			}
-			break
-		}
-	}
-
 	return rs
 }