cmd/go: use the rev to resolve tags for pseudo-versions in mod init

Fixes #32161
Updates #31251

Change-Id: I22760836b48cd734b90bc43aacb23e23e38c0f4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/178497
Reviewed-by: Bryan C. Mills <bcmills@google.com>

src/cmd/go/internal/modfetch/repo.go

@@ -319,7 +319,7 @@ func ImportRepoRev(path, rev string) (Repo, *RevInfo, error) {
 		return nil, nil, err
 	}
 
-	info, err := repo.(*codeRepo).convert(revInfo, "")
+	info, err := repo.(*codeRepo).convert(revInfo, rev)
 	if err != nil {
 		return nil, nil, err
 	}

src/cmd/go/testdata/script/mod_init_glide.txt

@@ -0,0 +1,32 @@
+env GO111MODULE=on
+
+[!net] skip
+[!exec:git] skip
+
+# test glide replacement
+go mod init x
+cmpenv go.mod go.mod.out
+
+-- main.go --
+package main
+
+import (
+	_ "github.com/rsc/legacytest"
+)
+
+func main() {}
+
+-- glide.lock --
+imports:
+- name: github.com/rsc/legacytest
+  version: fb3c628075e32f7f3c248a3abbdafd69ad6e21e1
+
+-- glide.yaml --
+package: x
+
+-- go.mod.out --
+module x
+
+go $goversion
+
+require github.com/rsc/legacytest v1.1.0-pre.0.20180717164849-fb3c628075e3