[Bug report] In some cases `islands.Length == 0` in `OptimizeTextureImpl::AfterAtlasSizesSmallToBig`#1424

AAO version: 1.8.7 NDMF version: 1.6.8 ``` System.InvalidOperationException: Sequence contains no elements at System.Linq.Enumerable.Max[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] selector) [0x00030] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AfterAtlasSizesSmallToBig (Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl+AtlasIsland[] islands) [0x00035] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:1017 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.MayAtlasTexture (System.Collections.Generic.ICollection`1[T] textures, System.Collections.Generic.ICollection`1[T] users, System.Nullable`1[T] wrapModeU, System.Nullable`1[T] wrapModeV) [0x000b4] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:545 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AtlasConnectedComponent (Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl+ConnectedComponentInfo info) [0x004df] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:380 at (wrapper unbox) Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AtlasConnectedComponent(Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl/ConnectedComponentInfo) at System.Linq.Enumerable+SelectManySingleSelectorIterator`2[TSource,TResult].ToList () [0x0001b] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at System.Linq.Enumerable.ToList[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0001f] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.Execute (nadena.dev.ndmf.BuildContext context, Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizeState state) [0x0002c] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:110 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTexture.Execute (nadena.dev.ndmf.BuildContext context, Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizeState state) [0x00009] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:25 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizePass`1[T].Execute (nadena.dev.ndmf.BuildContext context) [0x00010] in .\Packages\com.anatawa12.avatar-optimizer\Internal\TraceAndOptimizeBase\TraceAndOptimizeProcessor.cs:103 at nadena.dev.ndmf.Pass`1[T].nadena.dev.ndmf.IPass.Execute (nadena.dev.ndmf.BuildContext context) [0x00000] in .\Packages\nadena.dev.ndmf\Editor\API\Fluent\Pass.cs:64 at nadena.dev.ndmf.ConcretePass.Execute (nadena.dev.ndmf.BuildContext context) [0x00000] in .\Packages\nadena.dev.ndmf\Editor\API\Solver\PluginResolver.cs:39 at nadena.dev.ndmf.BuildContext.RunPass (nadena.dev.ndmf.ConcretePass pass) [0x00124] in .\Packages\nadena.dev.ndmf\Editor\API\BuildContext.cs:325 at System.Linq.Enumerable.Max[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] selector) [0x00030] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AfterAtlasSizesSmallToBig (Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl+AtlasIsland[] islands) [0x00035] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:1017 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.MayAtlasTexture (System.Collections.Generic.ICollection`1[T] textures, System.Collections.Generic.ICollection`1[T] users, System.Nullable`1[T] wrapModeU, System.Nullable`1[T] wrapModeV) [0x000b4] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:545 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AtlasConnectedComponent (Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl+ConnectedComponentInfo info) [0x004df] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:380 at (wrapper unbox) Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.AtlasConnectedComponent(Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl/ConnectedComponentInfo) at System.Linq.Enumerable+SelectManySingleSelectorIterator`2[TSource,TResult].ToList () [0x0001b] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at System.Linq.Enumerable.ToList[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0001f] in <70471b9615aa4ecfa3ed1abb95b73832>:0 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTextureImpl.Execute (nadena.dev.ndmf.BuildContext context, Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizeState state) [0x0002c] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:110 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.OptimizeTexture.Execute (nadena.dev.ndmf.BuildContext context, Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizeState state) [0x00009] in .\Packages\com.anatawa12.avatar-optimizer\Editor\Processors\TraceAndOptimize\OptimizeTexture.cs:25 at Anatawa12.AvatarOptimizer.Processors.TraceAndOptimizes.TraceAndOptimizePass`1[T].Execute (nadena.dev.ndmf.BuildContext context) [0x00010] in .\Packages\com.anatawa12.avatar-optimizer\Internal\TraceAndOptimizeBase\TraceAndOptimizeProcessor.cs:103 at nadena.dev.ndmf.Pass`1[T].nadena.dev.ndmf.IPass.Execute (nadena.dev.ndmf.BuildContext context) [0x00000] in .\Packages\nadena.dev.ndmf\Editor\API\Fluent\Pass.cs:64 at nadena.dev.ndmf.ConcretePass.Execute (nadena.dev.ndmf.BuildContext context) [0x00000] in .\Packages\nadena.dev.ndmf\Editor\API\Solver\PluginResolver.cs:39 at nadena.dev.ndmf.BuildContext.RunPass (nadena.dev.ndmf.ConcretePass pass) [0x00124] in .\Packages\nadena.dev.ndmf\Editor\API\BuildContext.cs:325