FileStream memory leak in ZipArchive (ZipSubRStream) when extracting files from archive.

[just-bank]

Problem: FileStream memory leak in ZipArchive (ZipSubRStream) when extracting files from archive.

Reproduce:
Using following code to track FileStream objects':

@@ -22,6 +22,7 @@
 
 #include "platform/platform.h"
 #include "core/stream/fileStream.h"
+#include "console/console.h"
 
 
 //-----------------------------------------------------------------------------
@@ -31,6 +32,7 @@
 //-----------------------------------------------------------------------------
 FileStream::FileStream()
 {
+   Con::warnf("Created FileStream 0x%16p", (this));
    dMemset(mBuffer, 0, sizeof(mBuffer));
    // initialize the file stream
    init();
@@ -54,8 +56,11 @@ FileStream *FileStream::createAndOpen(const String &inFileName, Torque::FS::File
 //-----------------------------------------------------------------------------
 FileStream::~FileStream()
 {
+   String temp = mFile ? mFile->getName().getFullPath().c_str() : "none";
    // make sure the file stream is closed
    close();
+
+   Con::printf("Dropping FileStream 0x%16p on %s", (this), temp.c_str());
 }
 
 //-----------------------------------------------------------------------------
@@ -145,6 +150,7 @@ bool FileStream::open(const String &inFileName, Torque::FS::File::AccessMode inM
       Torque::FS::CreatePath(filePath);
 
    mFile = Torque::FS::OpenFile(filePath, inMode);
+   Con::warnf("Opened FileStream 0x%16p on %s", (this), mFile->getName().getFullPath().c_str());
 
    if (mFile != NULL)
    {
@@ -190,6 +196,7 @@ void FileStream::close()
       if (mDirty)
          flush();
 
+      Con::printf("Closing FileStream 0x%16p on %s", (this), mFile->getName().getFullPath().c_str());
       // and close the file
       mFile->close();

Using script:

   // Create archive
   new ZipObject(zo);
   zo.openArchive("data/test.zpp", "write");
   zo.addFile("data/file.txt", "file.txt");
   zo.closeArchive();
   zo.delete();
   // Extract file to catch mem-leak
   new ZipObject(zo);
   zo.openArchive("data/test.zpp", "read");
   zo.extractFile("file.txt", "data/fileOut.txt");
   zo.closeArchive();
   zo.delete();

.zpp ext used to prevent T3D to auto-load archive.

The extracting script gives this output:

Created FileStream 0x0000022596C625A0
Opened FileStream 0x0000022596C625A0 on game:/data/test.zpp
Created FileStream 0x000000E54BEF3A60
Opened FileStream 0x000000E54BEF3A60 on game:/data/file.txt
Created FileStream 0x0000022596C6A9C0                         // Created but never deleted
Opened FileStream 0x0000022596C6A9C0 on game:/data/test.zpp   // Opened but never closed
Closing FileStream 0x000000E54BEF3A60 on game:/data/file.txt
Dropping FileStream 0x000000E54BEF3A60 on none
Closing FileStream 0x0000022596C625A0 on game:/data/test.zpp
Dropping FileStream 0x0000022596C625A0 on none

This PR fixes the issue by passing new flag to closeFile() method in order to delete root stream from the chain (which is cloned/leaked FileStream on top of the ZipSubRStream).

Added safety check to prevent deleting mStream in case the bool ZipSubRStream::attachStream(Stream* io_pSlaveStream) method returns passed stream instead of cloned one.