ole32: Check that the storage was opened with write access before creating a new…

dlls/ole32/storage32.c

@@ -914,6 +914,11 @@ HRESULT WINAPI StorageBaseImpl_CreateStream(
     else
       return STG_E_FILEALREADYEXISTS;
   }
+  else if (STGM_ACCESS_MODE(This->openFlags) == STGM_READ)
+  {
+    WARN("read-only storage\n");
+    return STG_E_ACCESSDENIED;
+  }
 
   /*
    * memset the empty property
@@ -1120,6 +1125,11 @@ HRESULT WINAPI StorageImpl_CreateStorage(
       return STG_E_FILEALREADYEXISTS;
     }
   }
+  else if (STGM_ACCESS_MODE(This->base.openFlags) == STGM_READ)
+  {
+    WARN("read-only storage\n");
+    return STG_E_ACCESSDENIED;
+  }
 
   /*
    * memset the empty property

dlls/ole32/tests/storage32.c

@@ -719,10 +719,8 @@ static void test_storage_refcount(void)
         r = IStorage_CreateStorage( stg2, stgname2, STGM_SHARE_EXCLUSIVE|STGM_READWRITE, 0, 0, &stg3 );
         ok(r == STG_E_ACCESSDENIED, "CreateStorage should have returned STG_E_ACCESSDENIED instead of 0x%08lx\n", r);
 
-        todo_wine {
         r = IStorage_CreateStream( stg2, stmname2, STGM_CREATE|STGM_SHARE_EXCLUSIVE, 0, 0, &stm );
         ok(r == STG_E_ACCESSDENIED, "CreateStream should have returned STG_E_ACCESSDENIED instead of 0x%08lx\n", r);
-        }
 
         IStorage_Release(stg2);