Fix issue 9980: FP nullPointerRedundantCheck - condition after while loop (cppcheck-opensource#2912)

pfultz2 · web-flow · commit f6399c4cba7a · 2020-11-20T09:36:09.000+01:00
diff --git a/lib/reverseanalyzer.cpp b/lib/reverseanalyzer.cpp
@@ -173,7 +173,7 @@ struct ReverseTraversal {
                 if (!continueB)
                     break;
                 valueFlowGenericForward(assignTop->astOperand2(), analyzer, settings);
-                tok = previousBeforeAstLeftmostLeaf(assignTop);
+                tok = previousBeforeAstLeftmostLeaf(assignTop)->next();
                 continue;
             }
             if (tok->str() == "}") {
diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp
@@ -105,6 +105,7 @@ class TestNullPointer : public TestFixture {
         TEST_CASE(nullpointer62);
         TEST_CASE(nullpointer63);
         TEST_CASE(nullpointer64);
+        TEST_CASE(nullpointer65); // #9980
         TEST_CASE(nullpointer_addressOf); // address of
         TEST_CASE(nullpointerSwitch); // #2626
         TEST_CASE(nullpointer_cast); // #4692
@@ -2011,6 +2012,26 @@ class TestNullPointer : public TestFixture {
         ASSERT_EQUALS("", errout.str());
     }
 
+    void nullpointer65() {
+        check("struct A {\n"
+              "    double get();\n"
+              "};\n"
+              "double x;\n"
+              "double run(A** begin, A** end) {\n"
+              "    A* a = nullptr;\n"
+              "    while (begin != end) {\n"
+              "        a = *begin;\n"
+              "        x = a->get();\n"
+              "        ++begin;\n"
+              "    }\n"
+              "    x = 0;\n"
+              "    if (a)\n"
+              "        return a->get();\n"
+              "    return 0;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void nullpointer_addressOf() { // address of
         check("void f() {\n"
               "  struct X *x = 0;\n"

Original file line number	Diff line number	Diff line change
`@@ -173,7 +173,7 @@ struct ReverseTraversal {`
`173`	`173`	`if (!continueB)`
`174`	`174`	`break;`
`175`	`175`	`valueFlowGenericForward(assignTop->astOperand2(), analyzer, settings);`
`176`		`- tok = previousBeforeAstLeftmostLeaf(assignTop);`
	`176`	`+ tok = previousBeforeAstLeftmostLeaf(assignTop)->next();`
`177`	`177`	`continue;`
`178`	`178`	`}`
`179`	`179`	`if (tok->str() == "}") {`