From d443ba4f537e06aac6d2730bb13d16906ac9a8da Mon Sep 17 00:00:00 2001
From: Harald Csaszar <harald.csaszar@pixelcloudgames.com>
Date: Wed, 15 Oct 2025 15:23:17 +0200
Subject: [PATCH] [csharp] Port of commits 139fd84 and 20d5ee6. Added
 allowMissingRegions to AtlasAttachmentLoader. See #2948.

---
 .../src/Attachments/AtlasAttachmentLoader.cs    | 17 ++++++++++++-----
 spine-csharp/src/SkeletonBinary.cs              |  6 +++---
 spine-csharp/src/package.json                   |  2 +-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/spine-csharp/src/Attachments/AtlasAttachmentLoader.cs b/spine-csharp/src/Attachments/AtlasAttachmentLoader.cs
index 65c41cfd9..160555e7d 100644
--- a/spine-csharp/src/Attachments/AtlasAttachmentLoader.cs
+++ b/spine-csharp/src/Attachments/AtlasAttachmentLoader.cs
@@ -37,10 +37,16 @@ namespace Spine {
 	/// </summary>
 	public class AtlasAttachmentLoader : AttachmentLoader {
 		private Atlas[] atlasArray;
+		public bool allowMissingRegions;
 
-		public AtlasAttachmentLoader (params Atlas[] atlasArray) {
-			if (atlasArray == null) throw new ArgumentNullException("atlas", "atlas array cannot be null.");
+		public AtlasAttachmentLoader (params Atlas[] atlasArray)
+			: this(false, atlasArray) {
+		}
+
+		public AtlasAttachmentLoader (bool allowMissingRegions, params Atlas[] atlasArray) {
+			if (atlasArray == null) throw new ArgumentNullException ("atlas", "atlas array cannot be null.");
 			this.atlasArray = atlasArray;
+			this.allowMissingRegions = allowMissingRegions;
 		}
 
 		private void LoadSequence (string name, string basePath, Sequence sequence) {
@@ -48,7 +54,8 @@ namespace Spine {
 			for (int i = 0, n = regions.Length; i < n; i++) {
 				string path = sequence.GetPath(basePath, i);
 				regions[i] = FindRegion(path);
-				if (regions[i] == null) throw new ArgumentException(string.Format("Region not found in atlas: {0} (region attachment: {1})", path, name));
+				if (regions[i] == null && !allowMissingRegions)
+					throw new ArgumentException(string.Format("Region not found in atlas: {0} (region attachment: {1})", path, name));
 			}
 		}
 
@@ -58,7 +65,7 @@ namespace Spine {
 				LoadSequence(name, path, sequence);
 			else {
 				AtlasRegion region = FindRegion(path);
-				if (region == null)
+				if (region == null && !allowMissingRegions)
 					throw new ArgumentException(string.Format("Region not found in atlas: {0} (region attachment: {1})", path, name));
 				attachment.Region = region;
 			}
@@ -71,7 +78,7 @@ namespace Spine {
 				LoadSequence(name, path, sequence);
 			else {
 				AtlasRegion region = FindRegion(path);
-				if (region == null)
+				if (region == null && !allowMissingRegions)
 					throw new ArgumentException(string.Format("Region not found in atlas: {0} (region attachment: {1})", path, name));
 				attachment.Region = region;
 			}
diff --git a/spine-csharp/src/SkeletonBinary.cs b/spine-csharp/src/SkeletonBinary.cs
index 497a2c580..c1d252b0c 100644
--- a/spine-csharp/src/SkeletonBinary.cs
+++ b/spine-csharp/src/SkeletonBinary.cs
@@ -461,7 +461,7 @@ namespace Spine {
 					if (parent == null) throw new Exception("Parent mesh not found: " + linkedMesh.parent);
 					linkedMesh.mesh.TimelineAttachment = linkedMesh.inheritTimelines ? (VertexAttachment)parent : linkedMesh.mesh;
 					linkedMesh.mesh.ParentMesh = (MeshAttachment)parent;
-					if (linkedMesh.mesh.Sequence == null) linkedMesh.mesh.UpdateRegion();
+					if (linkedMesh.mesh.Region != null) linkedMesh.mesh.UpdateRegion();
 				}
 				linkedMeshes.Clear();
 
@@ -568,7 +568,7 @@ namespace Spine {
 				region.height = height * scale;
 				region.SetColor(color.RGBA8888ToColor());
 				region.sequence = sequence;
-				if (sequence == null) region.UpdateRegion();
+				if (region.Region != null) region.UpdateRegion();
 				return region;
 			}
 			case AttachmentType.Boundingbox: {
@@ -609,7 +609,7 @@ namespace Spine {
 				mesh.WorldVerticesLength = vertices.length;
 				mesh.triangles = triangles;
 				mesh.regionUVs = uvs;
-				if (sequence == null) mesh.UpdateRegion();
+				if (mesh.Region != null) mesh.UpdateRegion();
 				mesh.HullLength = hullLength << 1;
 				mesh.Sequence = sequence;
 				if (nonessential) {
diff --git a/spine-csharp/src/package.json b/spine-csharp/src/package.json
index 83760f1cd..46375587f 100644
--- a/spine-csharp/src/package.json
+++ b/spine-csharp/src/package.json
@@ -2,7 +2,7 @@
 	"name": "com.esotericsoftware.spine.spine-csharp",
 	"displayName": "spine-csharp Runtime",
 	"description": "This plugin provides the spine-csharp core runtime.",
-	"version": "4.3.9",
+	"version": "4.3.10",
 	"unity": "2018.3",
 	"author": {
 		"name": "Esoteric Software",