1 files changed, 39 insertions, 0 deletions
diff --git a/libgo/go/cmd/go/testdata/script/mod_get_downgrade.txt b/libgo/go/cmd/go/testdata/script/mod_get_downgrade.txt
new file mode 100644
index 00000000000..ac814dae08f
--- /dev/null
+++ b/libgo/go/cmd/go/testdata/script/mod_get_downgrade.txt
@@ -0,0 +1,39 @@
+env GO111MODULE=on
+
+# downgrade sampler should downgrade quote
+go get rsc.io/sampler@v1.0.0
+go list -m all
+stdout 'rsc.io/quote v1.4.0'
+stdout 'rsc.io/sampler v1.0.0'
+
+# downgrade sampler away should downgrade quote further
+go get rsc.io/sampler@none
+go list -m all
+stdout 'rsc.io/quote v1.3.0'
+
+# downgrade should report inconsistencies and not change go.mod
+go get rsc.io/quote@v1.5.1
+go list -m all
+stdout 'rsc.io/quote v1.5.1'
+stdout 'rsc.io/sampler v1.3.0'
+! go get rsc.io/sampler@v1.0.0 rsc.io/quote@v1.5.2 golang.org/x/text@none
+stderr 'go get: inconsistent versions:\n\trsc.io/quote@v1.5.2 requires golang.org/x/text@v0.0.0-20170915032832-14c0d48ead0c \(not golang.org/x/text@none\), rsc.io/sampler@v1.3.0 \(not rsc.io/sampler@v1.0.0\)'
+go list -m all
+stdout 'rsc.io/quote v1.5.1'
+stdout 'rsc.io/sampler v1.3.0'
+
+# go get -u args should limit upgrades
+cp go.mod.empty go.mod
+go get -u rsc.io/quote@v1.4.0 rsc.io/sampler@v1.0.0
+go list -m all
+stdout 'rsc.io/quote v1.4.0'
+stdout 'rsc.io/sampler v1.0.0'
+! stdout golang.org/x/text
+
+-- go.mod --
+module x
+require rsc.io/quote v1.5.1
+-- go.mod.empty --
+module x
+-- x.go --
+package x