Tribes 2 // Mod Development Handbook GitHub

47 · teratos’ evoClassic

A redistribution of Evolution Admin Mod 1.2.3c, dated 8 June 2014 — ten years after the original — carrying exactly one change. It is the shortest section in this handbook and one of the most useful, because the change is a textbook instance of the single nastiest gotcha in TorqueScript.

The diff

Fingerprinting all 26 files against stock 1.2.3c:

   
Byte-identical 25
Modified 1 — scripts/evolution/defaultGame.ovl
Added 0
Removed 0

Both copies of defaultGame.ovl are 1604 lines. The file timestamps read 2004-05-13 and 2014-06-08. One line differs [mod-script]:

-      $TKLog = formatTimeString("d-M-yy") SPC formatTimeString("[HH:nn]") SPC %client.nameBase @ " (" @ getField(%authInfo, 0) @ ", " @ getField(%authInfo, 1) @ ", " @ %client.guid @ ", " @ %client.getAddress() @ ") TEAMKILLED " @ %victimID.nameBase;
+      $TKLog = formatTimeString("d-M-yy") SPC formatTimeString("[HH:nn]") SPC %killerID.nameBase @ " (" @ getField(%authInfo, 0) @ ", " @ getField(%authInfo, 1) @ ", " @ %killerID.guid @ ", " @ %killerID.getAddress() @ ") TEAMKILLED " @ %victimID.nameBase;

Three substitutions of %client for %killerID. That is the entire release.

Why it is a bug

Here is the function it lives in [mod-script]:

// DefaultGame::testTeamKill(%game, %victimID, %killerID)
// Info: Logs the teamkills. Overrides the original, so i need to use a package
function DefaultGame::testTeamKill(%game, %victimID, %killerID)
{
   %tk = Parent::testTeamKill(%game, %victimID, %killerID);
   if(!%tk)
      return false; // is not a tk

   if($Host::EvoTKLogging)
   {
      // get the TKer info
      %authInfo = %killerID.getAuthInfo();

      // TK info
      $TKLog = … %client.nameBase … %client.guid … %client.getAddress() … " TEAMKILLED " @ %victimID.nameBase;

There is no %client in scope. The parameters are %game, %victimID and %killerID. %client is never assigned anywhere in the function. It is not a misnamed variable pointing at the wrong player — it is a variable that does not exist.

TorqueScript locals need no declaration, and reading an unset one yields the empty string with no warning — the gotcha already catalogued in TorqueScript. So %client.nameBase, %client.guid and %client.getAddress() are method and field accesses on "", and all three produce nothing.

The log line the original actually wrote:

8-6-14 [21:14]  (SomeAuthName, SomeAuthField, , ) TEAMKILLED VictimName

The victim is named. The auth fields — taken from %killerID and therefore correct — are present. But the name, GUID and IP of the person who did it are blank.

An admin reading logs/TK/TKLog.txt sees a record of every teamkill on the server, correctly timestamped, naming the victim every time and the perpetrator never. The feature appears to work. Its output is formatted, populated, and useless for the one question it exists to answer.

Why it survived ten years

Three properties compounding:

It fails quietly. No console error, no script warning. An access on "" is legal TorqueScript.

The output looks right. Empty fields inside a formatted line with populated auth fields read as missing data, not as a code defect — plausibly a player who had not authenticated.

Nobody reads teamkill logs until they need one. The feature is consulted during a dispute, weeks later, by someone who does not have the source open. At that point the log is simply unhelpful, and the conclusion is “the logs are patchy”, not “line 331 references an undeclared local”.

The auth fields are what make it convincing. Whoever wrote it had %killerID correctly in hand one line earlier:

%authInfo = %killerID.getAuthInfo();

then reached for %client — the conventional name for a player connection across the entire Tribes 2 corpus, and the right name in most functions nearby. Muscle memory, in a language that will not tell you.

What to take from it

Prefer the parameter names you were given. If a function signature hands you %killerID, using %client inside it is a smell even when it works.

Test with !$= "" before dereferencing anything that came from somewhere else — TorqueScript gives the idiom. In a logging path this is cheap:

if(%killerID $= "")
   return %tk;   // nothing useful to log

Log lines are output whose correctness nobody checks. Diagnostics are the code least likely to be exercised in testing and most likely to matter later. Read one, once, after writing it.

A field that is always empty is a bug, not sparse data. If you are the admin reading these logs, “this column is never populated” should send you to the source.

Provenance and status

Distributed as evoClassic.vl2.zip from a Evolution&Pizza directory on tribes2stats.com — the naming reflecting Evolution’s own descent from Pizza Admin Mod (section 45).

The archive contains only the rebuilt evoClassic.vl2. It ships no readme, no changelog and no version marker — the one-line change is discoverable only by diffing. Treat it as Evolution 1.2.3c with a teamkill-logging fix; there is nothing else in it.

Whether to run it is straightforward: it is strictly better than stock 1.2.3c, and strictly a 1.2.3c-family mod. Everything in section 46 applies unchanged, including the WON-identity problem that limits the leasing system on a modern patched install. If you are standing up a server today, section 50 is the relevant page — the Evolution line is documented here for what it teaches, not as a current recommendation.