Fix FP constParameterReference, bad heuristic

cfg/std.cfg

@@ -4861,7 +4861,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     <noreturn>false</noreturn>
     <not-overlapping-data ptr1-arg="1" ptr2-arg="2" strlen-arg="2"/>
     <leak-ignore/>
-    <arg nr="1" direction="out">
+    <arg nr="1" direction="out" indirect="1">
       <not-null/>
       <minsize type="strlen" arg="2"/>
     </arg>

lib/astutils.cpp

@@ -2516,10 +2516,6 @@ bool isVariableChangedByFunctionCall(const Token *tok, int indirect, const Setti
         }
         if (Token::simpleMatch(tok->tokAt(-2), "std :: tie"))
             return true;
-        // if the library says 0 is invalid
-        // => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
-        if (indirect == 0 && requireNonNull)
-            return false;
         // possible pass-by-reference => inconclusive
         if (possiblyPassedByReference) {
             if (inconclusive != nullptr)

lib/library.cpp

@@ -749,6 +749,10 @@ Library::Error Library::loadFunction(const tinyxml2::XMLElement * const node, co
                 if (const char* const argIndirect = functionnode->Attribute("indirect")) {
                     const int indirect = strToInt<int>(argIndirect);
                     ac.direction[indirect] = dir; // TODO: handle multiple directions/indirect levels
+                    if (dir == ArgumentChecks::Direction::DIR_OUT) {
+                        for (int i = 0; i < indirect; ++i)
+                            ac.direction[i] = ArgumentChecks::Direction::DIR_IN; // ptr is not modified if pointed-to data are written
+                    }
                 }
                 else
                     ac.direction.fill(dir);

test/cfg/std.cpp

@@ -553,7 +553,6 @@ void bufferAccessOutOfBounds_std_ofstream_write(std::ofstream &os, const char* s
     (void)os.write(s,n);
 }
 
-// cppcheck-suppress constParameterReference // TODO: FP
 void bufferAccessOutOfBounds_std_ifstream_get(std::ifstream& in, std::streambuf& sb)
 {
     char cBuf[10];