[corlib] fix DefaultThreadCurrentCultureIsIgnoredWhenCultureFlowsToThread test

this test case was broken for an unknown time, but surfaced with a
recent change in nunit-lite (2255c54966b541095a93be16627e92acebf87215)
that runs every test in a new `ExecutionContext`. Previously, the
pre-condition for this test was implicility fulfilled by another test.
The test failed already when executed only on its own. With the change
around `ExecutionContext`, each test is "isolated" regarding said
pre-condition.

The fix is to explicitly fulfil the pre-condition in the test.

1 files changed, 8 insertions, 0 deletions

diff --git a/mcs/class/corlib/Test/System.Globalization/CultureInfoTest.cs b/mcs/class/corlib/Test/System.Globalization/CultureInfoTest.cs
index 766065b67be..188fc33b5e8 100644
--- a/mcs/class/corlib/Test/System.Globalization/CultureInfoTest.cs
+++ b/mcs/class/corlib/Test/System.Globalization/CultureInfoTest.cs
@@ -730,6 +730,14 @@ namespace MonoTests.System.Globalization
 			string us_str = null;
 			string br_str = null;
 
+			/* explicitly set CurrentCulture, as the documentation states:
+			 * > If you have not explicitly set the culture of any existing
+			 * > threads executing in an application domain, setting the
+			 * > P:System.Globalization.CultureInfo.DefaultThreadCurrentCulture
+			 * > property also changes the culture of these threads.
+			 */
+			Thread.CurrentThread.CurrentCulture = old_culture;
+
 			var thread = new Thread (() => {
 				CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("en-US");
 				us_str = 100000.ToString ("C");