ole32: Remove explicit type check in CommonPrefixWith() for item moniker.

dlls/ole32/itemmoniker.c

@@ -753,31 +753,19 @@ static HRESULT WINAPI ItemMonikerImpl_Inverse(IMoniker* iface,IMoniker** ppmk)
     return CreateAntiMoniker(ppmk);
 }
 
-/******************************************************************************
- *        ItemMoniker_CommonPrefixWith
- ******************************************************************************/
-static HRESULT WINAPI ItemMonikerImpl_CommonPrefixWith(IMoniker* iface,IMoniker* pmkOther,IMoniker** ppmkPrefix)
+static HRESULT WINAPI ItemMonikerImpl_CommonPrefixWith(IMoniker *iface, IMoniker *other,
+        IMoniker **prefix)
 {
-    DWORD mkSys;
-    
-    TRACE("(%p,%p)\n", pmkOther, ppmkPrefix);
-
-    IMoniker_IsSystemMoniker(pmkOther,&mkSys);
-    /* If the other moniker is an item moniker that is equal to this moniker, this method sets *ppmkPrefix */
-    /* to this moniker and returns MK_S_US */
-
-    if((mkSys==MKSYS_ITEMMONIKER) && (IMoniker_IsEqual(iface,pmkOther)==S_OK) ){
-
-        *ppmkPrefix=iface;
+    TRACE("%p, %p, %p\n", iface, other, prefix);
 
+    if (IMoniker_IsEqual(iface, other) == S_OK)
+    {
+        *prefix = iface;
         IMoniker_AddRef(iface);
-
         return MK_S_US;
     }
-    else
-        /* otherwise, the method calls the MonikerCommonPrefixWith function. This function correctly handles */
-        /* the case where the other moniker is a generic composite. */
-        return MonikerCommonPrefixWith(iface,pmkOther,ppmkPrefix);
+
+    return MonikerCommonPrefixWith(iface, other, prefix);
 }
 
 /******************************************************************************

dlls/ole32/tests/moniker.c

@@ -2276,7 +2276,7 @@ static void test_item_moniker(void)
         "Moniker_IsRunning",
         NULL
     };
-    IMoniker *moniker, *moniker2, *reduced, *anti, *inverse;
+    IMoniker *moniker, *moniker2, *moniker3, *reduced, *anti, *inverse;
     DWORD i, hash, eaten, cookie;
     HRESULT hr;
     IBindCtx *bindctx;
@@ -2611,6 +2611,34 @@ todo_wine
     IMoniker_Release(anti);
 
     IMoniker_Release(moniker);
+
+    /* CommonPrefixWith */
+    hr = CreateItemMoniker(L"!", L"Item", &moniker);
+    ok(hr == S_OK, "Failed to create a moniker, hr %#x.\n", hr);
+    hr = CreateItemMoniker(L"#", L"Item", &moniker2);
+    ok(hr == S_OK, "Failed to create a moniker, hr %#x.\n", hr);
+
+    hr = IMoniker_CommonPrefixWith(moniker, moniker2, &moniker3);
+    ok(hr == MK_S_US, "Unexpected hr %#x.\n", hr);
+    ok(moniker3 == moniker, "Unexpected object.\n");
+    IMoniker_Release(moniker3);
+
+    IMoniker_Release(moniker2);
+
+    hr = CreateItemMoniker(L"!", L"Item2", &moniker2);
+    ok(hr == S_OK, "Failed to create a moniker, hr %#x.\n", hr);
+
+    moniker3 = (void *)0xdeadbeef;
+    hr = IMoniker_CommonPrefixWith(moniker, moniker2, &moniker3);
+todo_wine
+{
+    ok(hr == MK_E_NOPREFIX, "Unexpected hr %#x.\n", hr);
+    ok(!moniker3, "Unexpected object.\n");
+}
+
+    IMoniker_Release(moniker2);
+
+    IMoniker_Release(moniker);
 }
 
 static void stream_write_dword(IStream *stream, DWORD value)