From c5f67a1f4e337e62ae65fe6785de806ff0760880 Mon Sep 17 00:00:00 2001
From: Matthew Stanley <1379tech@gmail.com>
Date: Sat, 24 Oct 2026 09:26:46 -0700
Subject: [PATCH] Cover source retirement and indexed texture fallback on
 current master

---
 runtime/src/gpu_hd_textures.cpp               |  2 +-
 runtime/src/hd_texture_pack.cpp               |  2 +-
 .../tests/test_duckstation_texture_pack.cpp   | 22 ++++++++++++++++++-
 runtime/tests/test_hd_texture_pack.cpp        | 19 ++++++++++++++++
 4 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/runtime/src/gpu_hd_textures.cpp b/runtime/src/gpu_hd_textures.cpp
index 85db9a97..3cdc2045 100644
--- a/runtime/src/gpu_hd_textures.cpp
+++ b/runtime/src/gpu_hd_textures.cpp
@@ -397,7 +397,7 @@ extern "C" void gpu_hd_textures_get_diag(GpuHdTextureDiag* out) {
     out->diagnostic = session->diagnostics.back().c_str();
 }
 extern "C" int gpu_hd_textures_debug_uploads_at(int x, int y, char* out, size_t cap) {
-    if (out && cap) out[0] = ' ';
+    if (out && cap) out[0] = '\0';
     return session ? hd_texture_pack_debug_uploads_at(session->beetle, (unsigned)x, (unsigned)y, out, cap) : 0;
 }
 extern "C" void gpu_hd_textures_note_applied(void) { if (session) ++session->diag.applied_draws; }
diff --git a/runtime/src/hd_texture_pack.cpp b/runtime/src/hd_texture_pack.cpp
index ce913671..5ae5dd1e 100644
--- a/runtime/src/hd_texture_pack.cpp
+++ b/runtime/src/hd_texture_pack.cpp
@@ -1082,7 +1082,7 @@ int hd_texture_pack_debug_uploads_at(const HdTexturePack* pack, unsigned x, unsi
     if (!out || cap == 0) return 0;
     size_t pos = 0;
     int n = 0;
-    out[0] = ' ';
+    out[0] = '\0';
     if (!pack) return 0;
     for (auto it = pack->uploads.rbegin(); it != pack->uploads.rend(); ++it) {
         for (const Fragment& f : it->fragments) {
diff --git a/runtime/tests/test_duckstation_texture_pack.cpp b/runtime/tests/test_duckstation_texture_pack.cpp
index f7f57639..9103f8c1 100644
--- a/runtime/tests/test_duckstation_texture_pack.cpp
+++ b/runtime/tests/test_duckstation_texture_pack.cpp
@@ -538,6 +538,26 @@ void split_coalesce_copy_parts(const fs::path& root) {
     check(duck_texture_pack_match_draw(pack.get(),&q,0,&match) == HD_TEXTURE_LOOKUP_NONE,"single-cover API preserves native fallback for composed draw");
 }
 
+void release_while_another_source_splits(const fs::path& root) {
+    config(root,"MaxVRAMWriteSplits: 4\nDumpC16Textures: true\nDumpTextureWidthThreshold: 1\nDumpTextureHeightThreshold: 1\n");
+    std::vector<uint16_t> vram(1024*512);
+    place(vram,0,0,4,words(16)); place(vram,8,0,8,words(64));
+    auto pack=create(root); char error[512]{};
+    duck_texture_pack_track_upload(pack.get(),0,0,4,4,vram.data(),vram.size());
+    duck_texture_pack_track_upload(pack.get(),8,0,8,8,vram.data(),vram.size());
+    auto first=query(vram,0,0,2,0,3,0,3);
+    auto second=query(vram,0,0,2,8,15,0,7);
+    duck_texture_pack_dump_draw(pack.get(),&first,0,error,sizeof error);
+    duck_texture_pack_dump_draw(pack.get(),&second,0,error,sizeof error);
+    DuckTexturePackInfo before{},after{}; duck_texture_pack_get_info(pack.get(),&before);
+    check(before.pending_dump_sources==2,"both independent source observations are pending");
+    // Retires the first upload entirely, while the second keeps right and lower clips.
+    duck_texture_pack_invalidate(pack.get(),0,0,12,4);
+    duck_texture_pack_get_info(pack.get(),&after);
+    check(after.pending_dump_sources==1 && after.queued_dump_count==1,
+          "released source finalizes even when surviving upload splits keep the total count steady");
+}
+
 void resident_checkpoint(const fs::path& root) {
     std::vector<uint16_t> vram(1024*512);
     place(vram,0,0,8,std::vector<uint16_t>(8*16,0x3210));
@@ -604,7 +624,7 @@ int main(int argc, char** argv) {
         palettes(root/"palettes"); st_alias_duplicates(root/"keys"); failed_payloads(root/"invalid"); dumping(root/"dump");
         official_binary_oracle(root/"official-oracle"); defaults_and_options(root/"defaults");
         immutable_palettes_and_pages(root/"snapshots"); split_coalesce_copy_parts(root/"lifecycle"); copied_pack_ownership(root/"ownership");
-        resident_checkpoint(root/"resident");
+        resident_checkpoint(root/"resident"); release_while_another_source_splits(root/"release-split");
         /* Every artifact is created beneath this fresh, explicitly named test
          * root. No user-provided paths participate in recursive cleanup. */
         if (argc > 1 && !std::strcmp(argv[1],"--keep-artifacts")) std::printf("ARTIFACT_ROOT: %s\n",root.u8string().c_str());
diff --git a/runtime/tests/test_hd_texture_pack.cpp b/runtime/tests/test_hd_texture_pack.cpp
index 6d952041..a3695756 100644
--- a/runtime/tests/test_hd_texture_pack.cpp
+++ b/runtime/tests/test_hd_texture_pack.cpp
@@ -211,6 +211,24 @@ HdTextureDrawQuery query4(const std::vector<uint16_t>& vram,
     return query;
 }
 
+void test_indexed_palette_fallback() {
+    Fixture f;
+    std::ostringstream stem; stem<<std::hex<<f.upload_hash;
+    touch(f.replacements/(stem.str()+"-index.png"));
+    auto* pack=open_pack(f.root); if(!pack)return;
+    hd_texture_pack_track_upload(pack,10,20,8,4,f.upload_words.data(),f.upload_words.size(),nullptr);
+    auto q=query4(f.vram,0,31); HdTextureMatch match{};
+    check(hd_texture_pack_match(pack,&q,&match)==HD_TEXTURE_LOOKUP_FOUND &&
+          match.entry.palette_hash==f.palette4_hash,"exact palette wins over indexed fallback");
+    f.vram[7*1024+1020]^=1;
+    hd_texture_pack_invalidate(pack,1020,7,1,1);
+    check(hd_texture_pack_match(pack,&q,&match)==HD_TEXTURE_LOOKUP_FOUND &&
+          match.entry.palette_hash==HD_TEXTURE_PALETTE_INDEXED,"changed CLUT uses palette-independent index key");
+    q.depth=HD_TEXTURE_DEPTH_16BPP; q.u_last=7;
+    check(hd_texture_pack_match(pack,&q,&match)==HD_TEXTURE_LOOKUP_NONE,"16bpp never uses indexed palette fallback");
+    hd_texture_pack_destroy(pack);
+}
+
 void test_crc_exact_little_endian() {
     const uint16_t ascii_words[] = {0x3231, 0x3433, 0x3635, 0x3837};
     check(hd_texture_crc32_words_le(ascii_words, 4) == 0x9AE0DAAFu,
@@ -516,6 +534,7 @@ void test_bounded_async_decode(Fixture& fixture) {
 
 int main() {
     test_crc_exact_little_endian();
+    test_indexed_palette_fallback();
     Fixture fixture;
     test_scan_mapping(fixture);
     test_palette_match_and_invalidation(fixture);