Merge pull request JuliaLang/julia#43084 from JuliaLang/backports-release-1.7

release-1.7: Backports for 1.7.0/1.7.0-rc4

Author: KristofferC

src/Test.jl

@@ -1275,6 +1275,7 @@ function testset_beginend(args, tests, source)
         # by wrapping the body in a function
         local RNG = default_rng()
         local oldrng = copy(RNG)
+        local oldseed = Random.GLOBAL_SEED
         try
             # RNG is re-seeded with its own seed to ease reproduce a failed test
             Random.seed!(Random.GLOBAL_SEED)
@@ -1288,6 +1289,7 @@ function testset_beginend(args, tests, source)
             record(ts, Error(:nontest_error, Expr(:tuple), err, Base.current_exceptions(), $(QuoteNode(source))))
         finally
             copy!(RNG, oldrng)
+            Random.set_global_seed!(oldseed)
             pop_testset()
             ret = finish(ts)
         end
@@ -1368,6 +1370,7 @@ function testset_forloop(args, testloop, source)
         local ts
         local RNG = default_rng()
         local oldrng = copy(RNG)
+        local oldseed = Random.GLOBAL_SEED
         Random.seed!(Random.GLOBAL_SEED)
         local tmprng = copy(RNG)
         try
@@ -1381,6 +1384,7 @@ function testset_forloop(args, testloop, source)
                 push!(arr, finish(ts))
             end
             copy!(RNG, oldrng)
+            Random.set_global_seed!(oldseed)
         end
         arr
     end

test/runtests.jl

@@ -869,6 +869,29 @@ end
     Random.seed!(seed)
     @test a == rand()
     @test b == rand()
+
+    # Even when seed!() is called within a testset A, subsequent testsets
+    # should start with the same "global RNG state" as what A started with,
+    # such that the test `refvalue == rand(Int)` below succeeds.
+    # Currently, this means that Random.GLOBAL_SEED has to be restored,
+    # in addition to the state of Random.default_rng().
+    GLOBAL_SEED_orig = Random.GLOBAL_SEED
+    local refvalue
+    @testset "GLOBAL_SEED is also preserved (setup)" begin
+        @test GLOBAL_SEED_orig == Random.GLOBAL_SEED
+        refvalue = rand(Int)
+        Random.seed!()
+        @test GLOBAL_SEED_orig != Random.GLOBAL_SEED
+    end
+    @test GLOBAL_SEED_orig == Random.GLOBAL_SEED
+    @testset "GLOBAL_SEED is also preserved (forloop)" for _=1:3
+        @test refvalue == rand(Int)
+        Random.seed!()
+    end
+    @test GLOBAL_SEED_orig == Random.GLOBAL_SEED
+    @testset "GLOBAL_SEED is also preserved (beginend)" begin
+        @test refvalue == rand(Int)
+    end
 end
 
 @testset "InterruptExceptions #21043" begin
@@ -1202,4 +1225,4 @@ Test.finish(ts::PassInformationTestSet) = ts
     @test ts.results[2].data == ErrorException
     @test ts.results[2].value == ErrorException("Msg")
     @test ts.results[2].source == LineNumberNode(test_throws_line_number, @__FILE__)
-end
+end