SDL: Save a copy of the D3D12 semantic string

SDL Commits
1 
From 4db63e323e37e6bb7df6a743999d1ded036553a8 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sun, 2 Nov 2025 16:15:20 -0800
Subject: [PATCH] Save a copy of the D3D12 semantic string

Fixes https://github.com/libsdl-org/SDL/issues/14383
---
 src/gpu/d3d12/SDL_gpu_d3d12.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/gpu/d3d12/SDL_gpu_d3d12.c b/src/gpu/d3d12/SDL_gpu_d3d12.c
index 985a82eee1f6c..0c76e79225c91 100644
--- a/src/gpu/d3d12/SDL_gpu_d3d12.c
+++ b/src/gpu/d3d12/SDL_gpu_d3d12.c
@@ -864,7 +864,7 @@ struct D3D12Renderer
     SDL_SharedObject *d3d12_dll;
     ID3D12Device *device;
     PFN_D3D12_SERIALIZE_ROOT_SIGNATURE pD3D12SerializeRootSignature;
-    const char *semantic;
+    char *semantic;
     SDL_iconv_t iconv;
 
     ID3D12CommandQueue *commandQueue;
@@ -1713,6 +1713,7 @@ static void D3D12_INTERNAL_DestroyRenderer(D3D12Renderer *renderer)
     SDL_DestroyMutex(renderer->windowLock);
     SDL_DestroyMutex(renderer->fenceLock);
     SDL_DestroyMutex(renderer->disposeLock);
+    SDL_free(renderer->semantic);
     SDL_free(renderer);
 }
 
@@ -9255,7 +9256,7 @@ static SDL_GPUDevice *D3D12_CreateDevice(bool debugMode, bool preferLowPower, SD
     renderer->debug_mode = debugMode;
     renderer->allowedFramesInFlight = 2;
 
-    renderer->semantic = SDL_GetStringProperty(props, SDL_PROP_GPU_DEVICE_CREATE_D3D12_SEMANTIC_NAME_STRING, "TEXCOORD");
+    renderer->semantic = SDL_strdup(SDL_GetStringProperty(props, SDL_PROP_GPU_DEVICE_CREATE_D3D12_SEMANTIC_NAME_STRING, "TEXCOORD"));
 
     // Blit resources
     D3D12_INTERNAL_InitBlitResources(renderer);