Changed, Visual mode: "Paste Selection" action (Ctrl-V) can now paste both copied textures and things, based on what was copied last.

Changed, Map Analysis mode: the view is now much more zoomed after clocking on a "Check very short linedefs" error check result.
Removed single testing engine launchable by the editor at once limitation (it worked properly only when using Test map actions anyway).
Fixed: re-did the fix for invalid geometry created when drawing very large grids from R2653, because it caused other issues.

Source/Core/Editing/ClassicMode.cs

@@ -719,7 +719,7 @@ namespace CodeImp.DoomBuilder.Editing
 
 				if(s == null)
 				{
-					General.MainWindow.DisplayStatus(StatusType.Warning, "Can't test from current position: cursor is not inside sector!");
+					General.MainWindow.DisplayStatus(StatusType.Warning, "Can't test from current position: mouse cursor must be inside a sector!");
 					return false;
 				}
 

Source/Core/GZBuilder/Data/EngineInfo.cs

@@ -100,7 +100,7 @@ namespace CodeImp.DoomBuilder.GZBuilder.Data
 			if(File.Exists(testprogram))
 			{
 				Icon i = Icon.ExtractAssociatedIcon(testprogram);
-				icon = (i != null ? i.ToBitmap() : new Bitmap(Properties.Resources.Question));
+				icon = new Bitmap(i != null ? i.ToBitmap() : Properties.Resources.Question);
 			}
 			else
 			{

Source/Core/Geometry/Tools.cs

@@ -939,7 +939,6 @@ namespace CodeImp.DoomBuilder.Geometry
 				if(points[0].stitch) mergeverts.Add(v1); else nonmergeverts.Add(v1);
 
 				// Go for all other points
-				int roundprecision = (General.Map.FormatInterface.VertexDecimals > 0 ? General.Map.FormatInterface.VertexDecimals - 1 : 0); //mxd
 				for(int i = 1; i < points.Count; i++)
 				{
 					// Create vertex for point
@@ -965,7 +964,7 @@ namespace CodeImp.DoomBuilder.Geometry
 						// Check if any other lines intersect this line
 						List<float> intersections = new List<float>();
 						Line2D measureline = ld.Line;
-						Dictionary<Linedef, bool> processed = new Dictionary<Linedef, bool>(); //mxd
+						HashSet<Linedef> processed = new HashSet<Linedef>(); //mxd
 
 						//mxd
 						foreach(Sector s in map.Sectors) 
@@ -975,7 +974,7 @@ namespace CodeImp.DoomBuilder.Geometry
 							{
 								foreach(Sidedef side in s.Sidedefs) 
 								{
-									if(processed.ContainsKey(side.Line)) continue;
+									if(processed.Contains(side.Line)) continue;
 									if(side.Line == ld) continue;
 
 									float u;
@@ -985,7 +984,7 @@ namespace CodeImp.DoomBuilder.Geometry
 										intersections.Add(u);
 									}
 
-									processed.Add(side.Line, false);
+									processed.Add(side.Line);
 								}
 							}
 						}
@@ -1002,10 +1001,6 @@ namespace CodeImp.DoomBuilder.Geometry
 							// may already have changed in length due to a previous split
 							Vector2D splitpoint = measureline.GetCoordinatesAt(u);
 
-							//mxd. Work around some imprecisions when splitting very long lines (like 19000 mu long)
-							splitpoint.x = (float)Math.Round(splitpoint.x, roundprecision);
-							splitpoint.y = (float)Math.Round(splitpoint.y, roundprecision);
-
 							// Make the vertex
 							Vertex splitvertex = map.CreateVertex(splitpoint);
 							if(splitvertex == null) return false;

Source/Core/Map/MapSet.cs

@@ -47,7 +47,7 @@ namespace CodeImp.DoomBuilder.Map
 
 		/// <summary>Stiching distance. This is only to get around inaccuracies. Basically,
 		/// geometry only stitches when exactly on top of each other.</summary>
-		public const float STITCH_DISTANCE = 0.001f;
+		public const float STITCH_DISTANCE = 0.005f; //mxd. 0.001f is not enough when drawing very long lines...
 		
 		// Virtual sector identification
 		// This contains a character that is invalid in the UDMF standard, but valid

Source/Plugins/BuilderModes/ErrorChecks/ResultShortLinedef.cs

@@ -1,6 +1,7 @@
 #region ================== Namespaces
 
 using System;
+using System.Drawing;
 using CodeImp.DoomBuilder.Map;
 using CodeImp.DoomBuilder.Rendering;
 
@@ -50,7 +51,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// This must return the string that is displayed in the listbox
 		public override string ToString()
 		{
-			return "Linedef " + line.Index + " is shorter than 1 m.u.";
+			return "Linedef " + line.Index + " is shorter than 1 mu.";
 		}
 		
 		// Rendering
@@ -61,6 +62,19 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			renderer.PlotVertex(line.End, ColorCollection.VERTICES);
 		}
 
+		// We must zoom in way more than usual...
+		public override RectangleF GetZoomArea()
+		{
+			// Get Area
+			RectangleF area = base.GetZoomArea();
+
+			// Remove padding
+			area.Inflate(-97f, -97f);
+
+			// Return area
+			return area;
+		}
+		
 		#endregion
 	}
 }

Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs

@@ -3001,7 +3001,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		public void TextureCopy()
 		{
 			PreActionNoChange();
-			GetTargetEventReceiver(true).OnCopyTexture(); //mxd
+			IVisualEventReceiver i = GetTargetEventReceiver(true);
+			i.OnCopyTexture(); //mxd
+			if(!(i is VisualThing)) copybuffer.Clear(); //mxd. Not copying things any more...
 			PostAction();
 		}
 
@@ -3434,7 +3436,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				VisualThing vt = (VisualThing)i;
 				if(vt != null) copybuffer.Add(new ThingCopyData(vt.Thing));
 			}
-			General.Interface.DisplayStatus(StatusType.Info, "Copied " + copybuffer.Count + " Things");
+
+			string rest = copybuffer.Count + (copybuffer.Count > 1 ? " things." : " thing.");
+			General.Interface.DisplayStatus(StatusType.Info, "Copied " + rest);
 		}
 
 		//mxd
@@ -3444,7 +3448,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			CopySelection();
 
 			//Create undo
-			string rest = copybuffer.Count + " thing" + (copybuffer.Count > 1 ? "s." : ".");
+			string rest = copybuffer.Count + (copybuffer.Count > 1 ? " things." : " thing.");
 			CreateUndo("Cut " + rest);
 			General.Interface.DisplayStatus(StatusType.Info, "Cut " + rest);
 
@@ -3470,7 +3474,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		{
 			if(copybuffer.Count == 0)
 			{
-				General.Interface.DisplayStatus(StatusType.Warning, "Nothing to paste, cut or copy some Things first!");
+				TexturePaste(); // I guess we may paste a texture or two instead
 				return;
 			}
 			
@@ -3482,7 +3486,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				return;
 			}
 
-			string rest = copybuffer.Count + " thing" + (copybuffer.Count > 1 ? "s" : "");
+			string rest = copybuffer.Count + (copybuffer.Count > 1 ? " things." : " thing.");
 			General.Map.UndoRedo.CreateUndo("Paste " + rest);
 			General.Interface.DisplayStatus(StatusType.Info, "Pasted " + rest);