Fixed false positive returnLocalVariable (#7180)

Author: PKEuS

lib/checkautovariables.cpp

@@ -117,7 +117,7 @@ bool CheckAutoVariables::isAutoVarArray(const Token *tok)
         return true;
 
     // ValueFlow
-    if (var->isPointer()) {
+    if (var->isPointer() && !var->isArgument()) {
         for (std::list<ValueFlow::Value>::const_iterator it = tok->values.begin(); it != tok->values.end(); ++it) {
             const ValueFlow::Value &val = *it;
             if (val.tokvalue && isAutoVarArray(val.tokvalue))

test/testautovariables.cpp

@@ -636,6 +636,16 @@ class TestAutoVariables : public TestFixture {
               "    return str;\n"
               "}");
         ASSERT_EQUALS("[test.cpp:7]: (error) Pointer to local array variable returned.\n", errout.str());
+
+        check("char * format_reg(char *outbuffer_start) {\n"
+              "    return outbuffer_start;\n"
+              "}\n"
+              "void print_with_operands() {\n"
+              "    char temp[42];\n"
+              "    char *tp = temp;\n"
+              "    tp = format_reg(tp);\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void returnLocalVariable2() {