Add a hack to avoid Error #001 when using WBFS

Regression from PR 8394, which made the behavior more accurate.
We need some sort of hack or heuristic for this since WBFS files
don't store the original disc size.

Source/Core/Core/HW/DVD/DVDInterface.cpp

@@ -174,6 +174,10 @@ static std::string s_disc_path_to_insert;
 static std::vector<std::string> s_auto_disc_change_paths;
 static size_t s_auto_disc_change_index;
 
+// Hacks
+static bool s_disc_has_accurate_size;
+static u64 s_guessed_disc_size;
+
 // Events
 static CoreTiming::EventType* s_finish_executing_command;
 static CoreTiming::EventType* s_auto_change_disc;
@@ -185,6 +189,8 @@ static void EjectDiscCallback(u64 userdata, s64 cyclesLate);
 static void InsertDiscCallback(u64 userdata, s64 cyclesLate);
 static void FinishExecutingCommandCallback(u64 userdata, s64 cycles_late);
 
+static u64 GuessDiscSize(const DiscIO::VolumeDisc& disc);
+
 void SetLidOpen();
 
 void UpdateInterrupts();
@@ -420,6 +426,35 @@ void Shutdown()
   DVDThread::Stop();
 }
 
+static u64 GuessDiscSize(const DiscIO::VolumeDisc& disc)
+{
+  // Many Wii games intentionally try to read from an offset which is just past the end of a regular
+  // DVD but just before the end of a DVD-R, displaying "Error #001" and failing to boot if the read
+  // succeeds (see https://wiibrew.org/wiki//dev/di#0x8D_DVDLowUnencryptedRead for more details).
+  //
+  // We normally handle this by checking whether the DiscIO code considers the read to be out of
+  // bounds (this is done in DVDThread.cpp), but this doesn't work correctly for disc image formats
+  // that don't store the original size of the disc, most notably WBFS. Because of this, we have a
+  // hack here that guesses the original size of the disc if necessary. For Wii discs, there are
+  // two possibilities: single-layer discs (4.7 GiB) and dual-layer discs (7.93 GiB). Thankfully,
+  // 0x30-0x34 in BI2 tells us which disc type the game is expecting: 0x7ED40000 (0x1FB500000 >> 2)
+  // for games that expect dual-layer, and 0x00000000 for other games. The game uses this value
+  // when determining whether the attempted out of bounds read should be at 0x118280000 (just past
+  // the end of a of a single-layer DVD) or at 0x1FB500000 (just past the end of a dual-layer DVD).
+  //
+  // An alternative hack that also would work (which was used in Dolphin in the past)
+  // is to always reject DVDLowUnencryptedRead commands other than ones before 0x50000,
+  // since Wii games never do any such reads with the expectation that they will work. However,
+  // this must not be done for the raw Read command (which is used by GC games and CleanRip).
+
+  if (disc.GetVolumeType() == DiscIO::Platform::GameCubeDisc)
+    return 0x57058000;
+
+  const std::optional<u32> value = disc.ReadSwapped<u32>(0x440 + 0x30, disc.GetGamePartition());
+  const bool dual_layer = value.has_value() && *value != 0;
+  return dual_layer ? 0x1FB4E0000 : 0x118240000;
+}
+
 void SetDisc(std::unique_ptr<DiscIO::VolumeDisc> disc,
              std::optional<std::vector<std::string>> auto_disc_change_paths = {})
 {
@@ -439,6 +474,10 @@ void SetDisc(std::unique_ptr<DiscIO::VolumeDisc> disc,
   if (had_disc != has_disc)
     ExpansionInterface::g_rtc_flags[ExpansionInterface::RTCFlag::DiscChanged] = true;
 
+  s_disc_has_accurate_size = has_disc && disc->IsSizeAccurate();
+  if (has_disc && !s_disc_has_accurate_size)
+    s_guessed_disc_size = GuessDiscSize(*disc);
+
   DVDThread::SetDisc(std::move(disc));
   SetLidOpen();
 
@@ -748,6 +787,18 @@ bool ExecuteReadCommand(u64 dvd_offset, u32 output_address, u32 dvd_length, u32
     dvd_length = output_length;
   }
 
+  if (SConfig::GetInstance().bWii && !s_disc_has_accurate_size &&
+      partition == DiscIO::PARTITION_NONE)
+  {
+    WARN_LOG(DVDINTERFACE, "Unknown disc size, guessing %" PRIu64 " bytes", s_guessed_disc_size);
+    if (dvd_offset + dvd_length > s_guessed_disc_size)
+    {
+      SetHighError(DVDInterface::ERROR_BLOCK_OOB);
+      *interrupt_type = DIInterruptType::DEINT;
+      return false;
+    }
+  }
+
   ScheduleReads(dvd_offset, dvd_length, partition, output_address, reply_type);
   return true;
 }