Merge pull request #5133 from amcasey/GH4138

Swallow ArgumentOutOfRangeException while retrieving custom debug info

src/Test/PdbUtilities/Shared/SymUnmanagedReaderExtensions.cs

@@ -156,17 +156,26 @@ private static void ValidateItems(int actualCount, int bufferLength)
         /// </summary>
         public static byte[] GetCustomDebugInfoBytes(this ISymUnmanagedReader reader, int methodToken, int methodVersion)
         {
-            return GetItems(
-                reader,
-                methodToken,
-                methodVersion,
-                (ISymUnmanagedReader pReader, int pMethodToken, int pMethodVersion, int pBufferLength, out int pCount, byte[] pCustomDebugInfo) =>
-                    // Note:  Here, we are assuming that the sym reader implementation we're using implements ISymUnmanagedReader3.  This is
-                    // necessary so that we get custom debug info for the correct method version in EnC scenarios.  However, some sym reader
-                    // implementations do not support this interface (for example, the mscordbi dynamic sym reader).  If we need to fall back
-                    // and call ISymUnmanagedReader.GetSymAttribute in those cases (assuming EnC is not supported), then we'll need to ensure
-                    // that incorrect or missing custom debug info will not cause problems for any callers of this method.
-                    ((ISymUnmanagedReader3)pReader).GetSymAttributeByVersion(pMethodToken, pMethodVersion, CdiAttributeName, pBufferLength, out pCount, pCustomDebugInfo));
+            try
+            {
+                return GetItems(
+                    reader,
+                    methodToken,
+                    methodVersion,
+                    (ISymUnmanagedReader pReader, int pMethodToken, int pMethodVersion, int pBufferLength, out int pCount, byte[] pCustomDebugInfo) =>
+                        // Note:  Here, we are assuming that the sym reader implementation we're using implements ISymUnmanagedReader3.  This is
+                        // necessary so that we get custom debug info for the correct method version in EnC scenarios.  However, some sym reader
+                        // implementations do not support this interface (for example, the mscordbi dynamic sym reader).  If we need to fall back
+                        // and call ISymUnmanagedReader.GetSymAttribute in those cases (assuming EnC is not supported), then we'll need to ensure
+                        // that incorrect or missing custom debug info will not cause problems for any callers of this method.
+                        ((ISymUnmanagedReader3)pReader).GetSymAttributeByVersion(pMethodToken, pMethodVersion, CdiAttributeName, pBufferLength, out pCount, pCustomDebugInfo));
+            }
+            catch (ArgumentOutOfRangeException)
+            {
+                // Sometimes the debugger returns the HRESULT for ArgumentOutOfRangeException, rather than E_FAIL,
+                // for methods without custom debug info (https://github.com/dotnet/roslyn/issues/4138).
+                return null;
+            }
         }
 
         public static int GetUserEntryPoint(this ISymUnmanagedReader symReader)