linux PIString fix

libs/main/core/pistring.cpp

@@ -233,18 +233,18 @@ void PIString::appendFromChars(const char * c, int s, const char * codepage) {
 #  else
 	mbstate_t state;
 	memset(&state, 0, sizeof(state));
-	char * pc;
+	const char ** pc;
 	if (s > 0) {
 		char c_ [s+1];
 		memcpy(c_, c, s);
 		c_[s] = '\0';
-		pc = c_;
+		pc = &c_;
 	} else {
-		pc = c;
+		pc = &c;
 	}
-	size_t len = mbsrtowcs(NULL, (const char**)&pc, 0, &state);
+	size_t len = mbsrtowcs(NULL, pc, 0, &state);
 	wchar_t wstr[len+1];
-	mbsrtowcs(&wstr[0], (const char**)&pc, len+1, &state);
+	mbsrtowcs(&wstr[0], pc, len+1, &state);
 	enlarge(len);
 	for (size_t i=0; i<len; ++i) (*this)[old_sz+i] = wstr[i];
 //	//qDebug() << "FromChars done" << size();