From 449c7bf7ef7097a86f1c08026f3d3a78228d12d4 Mon Sep 17 00:00:00 2001
From: andy <andy>
Date: Sat, 27 Mar 2004 18:26:55 +0000
Subject: [PATCH] Oops.  A last minute change broke piston engines.  The
 "phantom" fuel tanks created by the C++ code look empty, and were causing the
 fuel code to detect out of fuel conditions.  Since there is no way to tell a
 "FDM" tank from a "C++" tank, I just filter them by capacity.  Very ugly
 hack, we need to fix the code to report only the tanks created by the
 aircraft/FDM configuration.

---
 Nasal/fuel.nas | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/Nasal/fuel.nas b/Nasal/fuel.nas
index 2d615a998..a213c089a 100644
--- a/Nasal/fuel.nas
+++ b/Nasal/fuel.nas
@@ -35,11 +35,17 @@ fuelUpdate = func {
 
     AllTanks = props.globals.getNode("consumables/fuel").getChildren("tank");
 
-    # Build a list of selected tanks
+    # Build a list of selected tanks.  Note the filtering for
+    # "zero-capacity" tanks.  The FlightGear code likes to define
+    # zombie tanks that have no meaning to the FDM, so we have to take
+    # measures to ignore them here.
     selectedTanks = [];
     foreach(t; AllTanks) {
-        if(t.getNode("selected", 1).getBoolValue()) {
-            append(selectedTanks, t);
+        cap = t.getNode("capacity-gal_us", 1).getValue();
+        if(cap != nil and cap > 0.01) {
+            if(t.getNode("selected", 1).getBoolValue()) {
+                append(selectedTanks, t);
+            }
         }
     }
 
@@ -94,7 +100,7 @@ initialize = func {
     foreach(t; AllTanks) {
         initDoubleProp(t, "level-gal_us", 0);
         initDoubleProp(t, "level-lbs", 0);
-        initDoubleProp(t, "capacity-gal_us", 1); # Not zero (div/zero issue)
+        initDoubleProp(t, "capacity-gal_us", 0.01); # Not zero (div/zero issue)
         initDoubleProp(t, "density-ppg", 6.0); # gasoline
 
         if(t.getNode("selected") == nil) {