fix timeout tests

test/misc.jl

@@ -510,16 +510,31 @@ end
 
 # PR #28038 (prompt/getpass stream args)
 @test_throws MethodError Base.getpass(IOBuffer(), stdout, "pass")
-let buf = IOBuffer()
-    @test Base.prompt(IOBuffer("foo\nbar\n"), buf, "baz") == "foo"
-    @test String(take!(buf)) == "baz: "
-    @test Base.prompt(IOBuffer("\n"), buf, "baz", default="foobar") == "foobar"
-    @test String(take!(buf)) == "baz [foobar]: "
-    @test Base.prompt(IOBuffer("blah\n"), buf, "baz", default="foobar") == "blah"
-    take!(buf)
-    # prompt timeout
-    @test Base.prompt(stdin, buf, "baz", default="foobar", timeout = 1) == "foobar"
-    @test String(take!(buf)) == "baz [foobar] timeout 1 second: timed out\n"
+original_stdin = stdin
+try
+    let buf = IOBuffer()
+        @test Base.prompt(IOBuffer("foo\nbar\n"), buf, "baz") == "foo"
+        @test String(take!(buf)) == "baz: "
+        @test Base.prompt(IOBuffer("\n"), buf, "baz", default="foobar") == "foobar"
+        @test String(take!(buf)) == "baz [foobar]: "
+        @test Base.prompt(IOBuffer("blah\n"), buf, "baz", default="foobar") == "blah"
+        take!(buf)
+        # prompt timeout
+
+        (rd, wr) = redirect_stdin()
+        @test Base.prompt(rd, buf, "baz", default="foobar", timeout = 1) == "foobar"
+        @test String(take!(buf)) == "baz [foobar] timeout 1 second: timed out\n"
+        @test Base.prompt(rd, buf, "baz", default="foobar", timeout = 2) == "foobar"
+        @test String(take!(buf)) == "baz [foobar] timeout 2 seconds: timed out\n"
+        @test Base.prompt(IOBuffer("foo\n"), buf, "baz", default="foobar", timeout = 1) == "foo"
+        @test String(take!(buf)) == "baz [foobar] timeout 1 second: "
+        @test Base.prompt(IOBuffer("\n"), buf, "baz", default="foobar", timeout = 1) == "foobar"
+        @test String(take!(buf)) == "baz [foobar] timeout 1 second: "
+    end
+catch
+    rethrow()
+finally
+    redirect_stdin(original_stdin)
 end
 
 # these tests are not in a test block so that they will compile separately