From: Constantin Konstantinidis <constantinkonstantinidis@gmail.com>
Date: Sat, 5 Jun 2021 05:48:30 +0000 (+0200)
Subject: [release-branch.go1.16] cmd/go: remove hint when no module is suggested
X-Git-Tag: go1.16.7~4
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4c62fd36776c03547f7a9f8dc67c8dac8e987851;p=gostls13.git

[release-branch.go1.16] cmd/go: remove hint when no module is suggested

Updates #46528
Fixes #46551

Change-Id: I2453d321ece878ea7823865758aa4a16b3ed7fe8
Reviewed-on: https://go-review.googlesource.com/c/go/+/325430
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Trust: Heschi Kreinick <heschi@google.com>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
(cherry picked from commit e552a6d31270c86064632af1d092e0db5a930250)
Reviewed-on: https://go-review.googlesource.com/c/go/+/334371
Trust: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
---

diff --git a/src/cmd/go/internal/modload/import.go b/src/cmd/go/internal/modload/import.go
index 995641c9f1..eda0568f07 100644
--- a/src/cmd/go/internal/modload/import.go
+++ b/src/cmd/go/internal/modload/import.go
@@ -160,11 +160,13 @@ func (e *ImportMissingSumError) Error() string {
 		// Importing package is unknown, or the missing package was named on the
 		// command line. Recommend 'go mod download' for the modules that could
 		// provide the package, since that shouldn't change go.mod.
-		args := make([]string, len(e.mods))
-		for i, mod := range e.mods {
-			args[i] = mod.Path
+		if len(e.mods) > 0 {
+			args := make([]string, len(e.mods))
+			for i, mod := range e.mods {
+				args[i] = mod.Path
+			}
+			hint = fmt.Sprintf("; to add:\n\tgo mod download %s", strings.Join(args, " "))
 		}
-		hint = fmt.Sprintf("; to add:\n\tgo mod download %s", strings.Join(args, " "))
 	} else {
 		// Importing package is known (common case). Recommend 'go get' on the
 		// current version of the importing package.
diff --git a/src/cmd/go/testdata/script/mod_install_hint.txt b/src/cmd/go/testdata/script/mod_install_hint.txt
new file mode 100644
index 0000000000..ab02840eb8
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_install_hint.txt
@@ -0,0 +1,5 @@
+# Module is replaced but not required. No hint appears as no module is suggested.
+go mod init m
+go mod edit -replace=github.com/notrequired@v0.5.0=github.com/doesnotexist@v0.5.0
+! go install github.com/notrequired
+! stderr 'to add it:'
\ No newline at end of file