speaker entity does not handle invalid preset values correctly

[SamVanheer]

The speaker entity has a keyvalue preset used to select a predefined sound to play. The code to select this preset does not handle invalid values and will leave the sound name pointer uninitialized:

halflife/dlls/sound.cpp

Lines 1873 to 1894 in c7240b9

	if (m_preset)
	{
	// go lookup preset text, assign szSoundFile
	switch (m_preset)
	{
	case 1: szSoundFile = "C1A0_"; break;
	case 2: szSoundFile = "C1A1_"; break;
	case 3: szSoundFile = "C1A2_"; break;
	case 4: szSoundFile = "C1A3_"; break;
	case 5: szSoundFile = "C1A4_"; break;
	case 6: szSoundFile = "C2A1_"; break;
	case 7: szSoundFile = "C2A2_"; break;
	case 8: szSoundFile = "C2A3_"; break;
	case 9: szSoundFile = "C2A4_"; break;
	case 10: szSoundFile = "C2A5_"; break;
	case 11: szSoundFile = "C3A1_"; break;
	case 12: szSoundFile = "C3A2_"; break;
	}
	} else
	szSoundFile = (char*) STRING(pev->message);
	if (szSoundFile[0] == '!')

To fix this an additional case is required:

if (m_preset)
{
	// go lookup preset text, assign szSoundFile
	switch (m_preset)
	{
	case 1: szSoundFile =  "C1A0_"; break;
	case 2: szSoundFile =  "C1A1_"; break;
	case 3: szSoundFile =  "C1A2_"; break;
	case 4: szSoundFile =  "C1A3_"; break;
	case 5: szSoundFile =  "C1A4_"; break; 
	case 6: szSoundFile =  "C2A1_"; break;
	case 7: szSoundFile =  "C2A2_"; break;
	case 8: szSoundFile =  "C2A3_"; break;
	case 9: szSoundFile =  "C2A4_"; break;
	case 10: szSoundFile = "C2A5_"; break;
	case 11: szSoundFile = "C3A1_"; break;
	case 12: szSoundFile = "C3A2_"; break;
	default: szSoundFile = ""; break;
	}
}
else
	szSoundFile = (char*) STRING(pev->message);

Initializing it to an empty string will cause it to enter this branch:

halflife/dlls/sound.cpp

Lines 1903 to 1915 in c7240b9

	else
	{
	// make random announcement from sentence group
	if (SENTENCEG_PlayRndSz(ENT(pev), szSoundFile, flvolume, flattenuation, flags, pitch) < 0)
	ALERT(at_console, "Level Design Error!\nSPEAKER has bad sentence group name: %s\n",szSoundFile);
	// set next announcement time for random 5 to 10 minute delay
	pev->nextthink = gpGlobals->time +
	RANDOM_FLOAT(ANNOUNCE_MINUTES_MIN * 60.0, ANNOUNCE_MINUTES_MAX * 60.0);
	CTalkMonster::g_talkWaitTime = gpGlobals->time + 5; // time delay until it's ok to speak: used so that two NPCs don't talk at once
	}

Since there is no way for there to be a sentence group with an empty name nothing will be played and the error message in the code above will be printed.