Fixed #4118 (False null-pointer warning when check is indirect)

lib/checknullpointer.cpp

@@ -949,6 +949,14 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
                 break;
             }
 
+            // Bailout for "if".
+            if (tok2->str() == "if") {
+                if (_settings->inconclusive)
+                    inconclusive = true;
+                else
+                    break;
+            }
+
             if (Token::Match(tok2, "goto|continue|break|switch|for"))
                 break;
 

test/testnullpointer.cpp

@@ -1475,6 +1475,14 @@ private:
               "}");
         ASSERT_EQUALS("", errout.str());
 
+        // #4118 - second if
+        check("void f(char *p) {\n"
+              "    int x = 1;\n"
+              "    if (!p) x = 0;\n"
+              "    if (x) *p = 0;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
         // #2582 - segmentation fault
         check("if()");