Bypass incautious accessors (really fixes #33)

GameData/Astrogator/Astrogator-Changelog.cfg

@@ -10,6 +10,11 @@ KERBALCHANGELOG
 		version = 1.0.2
 		versionName = As if it never happened
 		versionKSP = 1.12
+		CHANGE
+		{
+			change = Better fixes for FlightGlobals NREs
+			type = Fix
+		}
 	}
 
 	VERSION

Source/AstrogatorMenu.cs

@@ -19,9 +19,7 @@ public class AstrogatorMenu : InternalModule {
 		AstrogatorMenu()
 			: base()
 		{
-			model = new AstrogationModel(
-				DefaultIfThrows<ITargetable>(() => FlightGlobals.ActiveVessel)
-				?? FlightGlobals.getMainBody());
+			model = new AstrogationModel(GetBestOrigin());
 			loader = new AstrogationLoadBehaviorette(model, null);
 			timeToWait = new List<DateTimeParts>();
 			cursorTransfer = 0;

Source/EnumerableExtensions.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+
+namespace Astrogator {
+
+	/// <summary>
+	/// Going to extra effort to be lazy
+	/// </summary>
+	public static class EnumerableExtensions
+	{
+
+		/// <summary>
+		/// Return the first element in a sequence matching a predicate,
+		/// or the the first element at all if none match.
+		/// </summary>
+		/// <typeparam name="T">The type of elements in the sequence</typeparam>
+		/// <param name="source">The sequence to scan, may be checked twice</param>
+		/// <param name="predicate">The predicate to check per element</param>
+		/// <returns></returns>
+		public static T FirstOrDefaultOrFirst<T>(this IEnumerable<T> source, Func<T, bool> predicate)
+			where T : class
+			=> source.FirstOrDefault(predicate) ?? source.FirstOrDefault();
+
+	}
+
+}

Source/KerbalTools.cs

@@ -245,6 +245,14 @@ public static CelestialBody ParentBody(ITargetable target)
 			}
 		}
 
+		/// <summary>
+		/// Get the active vessel, or the home world, or just the first world in the list, or null.
+		/// Works around FlightGlobals' broken singleton implementation.
+		/// </summary>
+		public static ITargetable GetBestOrigin()
+			=> (ITargetable)FlightGlobals.fetch?.activeVessel
+				?? FlightGlobals.fetch?.bodies?.FirstOrDefaultOrFirst(b => b?.isHomeWorld ?? false);
+
 		/// <summary>
 		/// Find the orbit that contains the given orbit.
 		/// Wrapper around Orbit.referenceBody that returns
@@ -316,24 +324,5 @@ public static string FilePath(string filename, bool GameDataRelative = true)
 			}
 		}
 
-		/// <summary>Discard annoying exceptions</summary>
-		/// <param name="func">The function to evaluate</param>
-		/// <returns>
-		///   The return value of func
-		///   or the default of its return type (typically null)
-		///   if it throws an exception
-		/// </returns>
-		public static T DefaultIfThrows<T>(Func<T> func)
-		{
-			try
-			{
-				return func();
-			}
-			catch
-			{
-				return default;
-			}
-		}
-
 	}
 }