.dot files sometimes rejected by writer

because CWW8 appears twice, once for normal .doc and once for .dot. So a .dot
files is tested twice if it's supported by the WW8 filter. Depending on the
(effectively arbitrary) order they appear in the list .dots may fail the "is a
normal non template .doc" test after the "is a template .dot" test and get
rejected as a CWW8 candidate.

Change-Id: I88aec29fdd5f9ec4dd4ad2813ff3c6b8fa5c5461

sw/source/filter/basflt/iodetect.cxx

@@ -260,6 +260,12 @@ sal_Bool SwIoSystem::IsFileFilter(SfxMedium& rMedium, const String& rFmtName)
                     }
                 }
             }
+            //The same underlying filter can appear multiple times in the
+            //filter list, e.g. CWW8 filter twice, once for .doc and once for
+            //.dot.  We just care here if its either, not enforce that it's
+            //both which would be a bit of an odd requirement
+            if (bRet)
+                break;
         }
 
         pFltr = aIter.Next();