Fix #14715 FP invalidFunctionArgStr, buffer is nul-terminated in every path (cppcheck-opensource#8516)

Author: chrchr-github

lib/checkfunctions.cpp

@@ -153,7 +153,7 @@ void CheckFunctions::invalidFunctionUsage()
                     // Is non-null terminated local variable of type char (e.g. char buf[] = {'x'};) ?
                     if (variable && variable->isLocal()
                         && valueType && (valueType->type == ValueType::Type::CHAR || valueType->type == ValueType::Type::WCHAR_T)
-                        && !isVariablesChanged(variable->declEndToken(), functionToken, 0 /*indirect*/, { variable }, *mSettings)) {
+                        && !isVariablesChanged(variable->declEndToken(), functionToken, valueType->pointer, { variable }, *mSettings)) {
                         const Token* varTok = variable->declEndToken();
                         MathLib::bigint count = -1; // Find out explicitly set count, e.g.: char buf[3] = {...}. Variable 'count' is set to 3 then.
                         if (varTok && Token::simpleMatch(varTok->astOperand1(), "["))

test/testfunctions.cpp

@@ -761,6 +761,13 @@ class TestFunctions : public TestFixture {
               "}\n");
         ASSERT_EQUALS("", errout_str());
 
+        check("char* f() {\n" // #14715
+              "    char a[3] = { 'a', 'b', 'c' };\n"
+              "    *a = 0;\n"
+              "    return strdup(a);\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
+
         check("size_t f() { wchar_t x = L'x'; return wcslen(&x); }");
         ASSERT_EQUALS("[test.cpp:1:46]: (error) Invalid wcslen() argument nr 1. A nul-terminated string is required. [invalidFunctionArgStr]\n", errout_str());