Fix String.IsInterned regression (#99389)

Introduced by FCall to QCall conversion Fixes #99386
dotnet · Mar 7, 2024 · 4e86b1c · 4e86b1c
1 parent ea2532e
commit 4e86b1c
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/src/coreclr/System.Private.CoreLib/src/System/String.CoreCLR.cs b/src/coreclr/System.Private.CoreLib/src/System/String.CoreCLR.cs
@@ -23,13 +23,12 @@ public static string Intern(string str)
         }
 
         [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "String_IsInterned")]
-        [return: MarshalAs(UnmanagedType.Bool)]
         private static partial void IsInterned(StringHandleOnStack src);
 
         public static string? IsInterned(string str)
         {
             ArgumentNullException.ThrowIfNull(str);
-            Intern(new StringHandleOnStack(ref str!));
+            IsInterned(new StringHandleOnStack(ref str!));
             return str;
         }
 

diff --git a/src/libraries/Common/tests/Tests/System/StringTests.cs b/src/libraries/Common/tests/Tests/System/StringTests.cs
@@ -7612,7 +7612,7 @@ public static unsafe void InternTest()
         }
 
         [Fact]
-        public static void InternalTestAotSubset()
+        public static void InternTestAotSubset()
         {
 #pragma warning disable 0618 // suppress obsolete warning for String.Copy
             string emptyFromField = string.Empty;
@@ -7629,6 +7629,17 @@ public static void InternalTestAotSubset()
 #pragma warning restore 0618 // restore warning when accessing obsolete members
         }
 
+        [Fact]
+        public static void InternTestCanReturnNull()
+        {
+            for (int i = 0; i < 20; i++)
+            {
+                if (string.IsInterned(Guid.NewGuid().ToString()) == null)
+                    return;
+            }
+            Assert.Fail("string.IsInterned never returns null");
+        }
+
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsNotInvariantGlobalization))]
         [ActiveIssue("https://github.com/dotnet/runtime/issues/34577", TestPlatforms.Windows, TargetFrameworkMonikers.Netcoreapp, TestRuntimes.Mono)]
         public static unsafe void NormalizationTest() // basic test; more tests in globalization tests