forcepoint #1

Thanks to Antti Levomäki and Christian Jalio from Forcepoint.

Change-Id: Ic5e9a9d0f8f8d35cb6b39e68338ba029948a4ce0
Reviewed-on: https://gerrit.libreoffice.org/50053
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

hwpfilter/source/hwpfile.h

@@ -227,7 +227,7 @@ class DLLEXPORT HWPFile
         HWPInfo& GetHWPInfo(void) { return _hwpInfo; }
         HWPFont& GetHWPFont(void) { return _hwpFont; }
         HWPStyle& GetHWPStyle(void) { return _hwpStyle; }
-        HWPPara *GetFirstPara(void) { return plist.front().get(); }
+        HWPPara *GetFirstPara(void) { return !plist.empty() ? plist.front().get() : nullptr; }
 
         EmPicture *GetEmPicture(Picture *pic);
         EmPicture *GetEmPictureByName(char * name);