Add test for ocaml#5925

NV_VARS5925_1 thru _4 should all be foo (i.e. without no colon)

tests/reftests/env.test

@@ -81,6 +81,18 @@ setenv: [
   [ NV_VARS3 := "foo" ]
   [ NV_VARS4  = ""    ]
   [ NV_VARS5 += ""    ] # undefined in the environment
+  [ NV_VARS_5925_1 = ""     ]
+  [ NV_VARS_5925_1 += "foo" ] # initialised to "" by opam
+  [ NV_VARS_5925_2 += "foo" ] # unset in the environment
+  [ NV_VARS_5925_3 = ""     ]
+  [ NV_VARS_5925_3 =+ "foo" ] # initialised to "" by opam
+  [ NV_VARS_5925_4 =+ "foo" ] # unset in the environment
+  [ NV_VARS_5925_5 = ""     ]
+  [ NV_VARS_5925_5 := "foo" ] # initialised to "" by opam
+  [ NV_VARS_5925_6 := "foo" ] # unset in the environment
+  [ NV_VARS_5925_7 = ""     ]
+  [ NV_VARS_5925_7 =: "foo" ] # initialised to "" by opam
+  [ NV_VARS_5925_8 =: "foo" ] # unset in the environment
 ]
 flags: compiler
 ### opam switch create emptyvar nv
@@ -95,12 +107,36 @@ Done.
 NV_VARS=
 NV_VARS3=foo:
 NV_VARS4=
+NV_VARS_5925_1=foo:
+NV_VARS_5925_2=foo
+NV_VARS_5925_3=:foo
+NV_VARS_5925_4=foo
+NV_VARS_5925_5=foo:
+NV_VARS_5925_6=foo:
+NV_VARS_5925_7=:foo
+NV_VARS_5925_8=:foo
 ### opam env | sort | grep "NV_VARS" | ';' -> ':'
 NV_VARS3='foo:': export NV_VARS3:
 NV_VARS4='': export NV_VARS4:
+NV_VARS_5925_1='foo:': export NV_VARS_5925_1:
+NV_VARS_5925_2='foo': export NV_VARS_5925_2:
+NV_VARS_5925_3=':foo': export NV_VARS_5925_3:
+NV_VARS_5925_4='foo': export NV_VARS_5925_4:
+NV_VARS_5925_5='foo:': export NV_VARS_5925_5:
+NV_VARS_5925_6='foo:': export NV_VARS_5925_6:
+NV_VARS_5925_7=':foo': export NV_VARS_5925_7:
+NV_VARS_5925_8=':foo': export NV_VARS_5925_8:
 ### opam exec -- opam env --revert | grep "NV_VARS" | ';' -> ':'
 NV_VARS3='': export NV_VARS3:
 NV_VARS4='': export NV_VARS4:
+NV_VARS_5925_1='': export NV_VARS_5925_1:
+NV_VARS_5925_2='': export NV_VARS_5925_2:
+NV_VARS_5925_3='': export NV_VARS_5925_3:
+NV_VARS_5925_4='': export NV_VARS_5925_4:
+NV_VARS_5925_5='': export NV_VARS_5925_5:
+NV_VARS_5925_6='': export NV_VARS_5925_6:
+NV_VARS_5925_7='': export NV_VARS_5925_7:
+NV_VARS_5925_8='': export NV_VARS_5925_8:
 ### NV_VARS=/another/path
 ### NV_VARS2=/another/different/path
 ### NV_VARS3=/yet/another/different/path
@@ -110,12 +146,36 @@ NV_VARS=/another/path
 NV_VARS2=/another/different/path
 NV_VARS3=foo:/yet/another/different/path
 NV_VARS4=
+NV_VARS_5925_1=foo:
+NV_VARS_5925_2=foo
+NV_VARS_5925_3=:foo
+NV_VARS_5925_4=foo
+NV_VARS_5925_5=foo:
+NV_VARS_5925_6=foo:
+NV_VARS_5925_7=:foo
+NV_VARS_5925_8=:foo
 ### opam env | sort | grep "NV_VARS" | ';' -> ':'
 NV_VARS3='foo:/yet/another/different/path': export NV_VARS3:
 NV_VARS4='': export NV_VARS4:
+NV_VARS_5925_1='foo:': export NV_VARS_5925_1:
+NV_VARS_5925_2='foo': export NV_VARS_5925_2:
+NV_VARS_5925_3=':foo': export NV_VARS_5925_3:
+NV_VARS_5925_4='foo': export NV_VARS_5925_4:
+NV_VARS_5925_5='foo:': export NV_VARS_5925_5:
+NV_VARS_5925_6='foo:': export NV_VARS_5925_6:
+NV_VARS_5925_7=':foo': export NV_VARS_5925_7:
+NV_VARS_5925_8=':foo': export NV_VARS_5925_8:
 ### opam exec -- opam env --revert | grep "NV_VARS" | ';' -> ':'
 NV_VARS3='/yet/another/different/path': export NV_VARS3:
 NV_VARS4='': export NV_VARS4:
+NV_VARS_5925_1='': export NV_VARS_5925_1:
+NV_VARS_5925_2='': export NV_VARS_5925_2:
+NV_VARS_5925_3='': export NV_VARS_5925_3:
+NV_VARS_5925_4='': export NV_VARS_5925_4:
+NV_VARS_5925_5='': export NV_VARS_5925_5:
+NV_VARS_5925_6='': export NV_VARS_5925_6:
+NV_VARS_5925_7='': export NV_VARS_5925_7:
+NV_VARS_5925_8='': export NV_VARS_5925_8:
 ### : Full revert of uninstalled package with setenv :
 ### <pkg:foo.1>
 opam-version: "2.0"
@@ -171,6 +231,14 @@ Done.
 ### opam env --root "$RT" --switch "./$SW" | grep "NV_VARS" | ';' -> ':'
 NV_VARS3='foo:/yet/another/different/path': export NV_VARS3:
 NV_VARS4='': export NV_VARS4:
+NV_VARS_5925_1='foo:': export NV_VARS_5925_1:
+NV_VARS_5925_2='foo': export NV_VARS_5925_2:
+NV_VARS_5925_3=':foo': export NV_VARS_5925_3:
+NV_VARS_5925_4='foo': export NV_VARS_5925_4:
+NV_VARS_5925_5='foo:': export NV_VARS_5925_5:
+NV_VARS_5925_6='foo:': export NV_VARS_5925_6:
+NV_VARS_5925_7=':foo': export NV_VARS_5925_7:
+NV_VARS_5925_8=':foo': export NV_VARS_5925_8:
 ### OPAMNOENVNOTICE=1
 ### : Env hooks :
 ### <pkg:av.1>