Fix ahnyQuab ogg decompression crashes.

This issue was introduced when `hsStream::Close()` was removed in favor
of RAII. Unfortunately, the patcher is handing off files before it
deletes the patcher stream, which causes race conditions around zlib
decompression not being complete. We need to explicitly close the
underlying stream before performing any handoffs to prevent crashes.

Sources/Plasma/FeatureLib/pfPatcher/pfPatcher.cpp

@@ -264,6 +264,13 @@ class pfPatcherStream : public plZlibStream
         return retVal;
     }
 
+    void Close()
+    {
+        if (hsCheckBits(fFlags, kFlagZipped))
+            plZlibStream::Close();
+        fOutput.reset();
+    }
+
     uint32_t Write(uint32_t count, const void* buf) override
     {
         // tick whatever progress bar we have
@@ -383,6 +390,14 @@ static void IFileThingDownloadCB(ENetError result, void* param, const plFileName
     pfPatcherWorker* patcher = static_cast<pfPatcherWorker*>(param);
     pfPatcherStream* stream = static_cast<pfPatcherStream*>(writer);
 
+    // We need to explicitly close any underlying streams NOW because we
+    // might be about to signal the client that this file needs to be acted
+    // on, eg installed, decompressed from ogg to wave, etc. We can't wait
+    // for hsStream's RAII to close the stream at the end of this function or
+    // the callback code may crash due to either a permissions error or the
+    // zlib decompression not being complete.
+    stream->Close();
+
     if (IS_NET_SUCCESS(result)) {
         PatcherLogGreen("\tDownloaded File '{}'", stream->GetFileName());
         patcher->WhitelistFile(stream->GetFileName(), true);