Fixed #2443 (Possible null pointer dereference: xxx - otherwise it is redundant to check if xxx is null at line)

lib/checknullpointer.cpp

@@ -461,6 +461,11 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
                     break;
                 }
 
+                if (tok1->str() == ")" && Token::Match(tok1->link()->previous(), "while ( %varid%", varid))
+                {
+                    break;
+                }
+
                 if (tok1->varId() == varid && !Token::Match(tok1->previous(), "[?:]"))
                 {
                     // unknown : this is set by isPointerDeRef if it is

test/testnullpointer.cpp

@@ -405,6 +405,18 @@ private:
               "        ;\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("BOOL GotoFlyAnchor()\n"  // #2243
+              "{\n"
+              "    const SwFrm* pFrm = GetCurrFrm();\n"
+              "    do {\n"
+              "        pFrm = pFrm->GetUpper();\n"
+              "    } while( pFrm && !pFrm->IsFlyFrm() );\n"
+              "\n"
+              "    if( !pFrm )\n"
+              "        return FALSE;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void nullpointer5()