1 files changed, 16 insertions, 6 deletions

diff --git a/dep/CascLib/src/CascDecompress.cpp b/dep/CascLib/src/CascDecompress.cpp
index e60adb8f97b..3262c59ddf7 100644
--- a/dep/CascLib/src/CascDecompress.cpp
+++ b/dep/CascLib/src/CascDecompress.cpp
@@ -18,29 +18,39 @@
 int CascDecompress(LPBYTE pbOutBuffer, PDWORD pcbOutBuffer, LPBYTE pbInBuffer, DWORD cbInBuffer)
 {
     z_stream z;                        // Stream information for zlib
+    uInt cbOutBuffer = *pcbOutBuffer;
     int nResult;
+    int nError = ERROR_FILE_CORRUPT;
 
     // Fill the stream structure for zlib
     z.next_in   = pbInBuffer;
     z.avail_in  = cbInBuffer;
     z.total_in  = cbInBuffer;
     z.next_out  = pbOutBuffer;
-    z.avail_out = *pcbOutBuffer;
+    z.avail_out = cbOutBuffer;
     z.total_out = 0;
     z.zalloc    = NULL;
     z.zfree     = NULL;
 
+    // Reset the total number of output bytes
+    cbOutBuffer = 0;
+
     // Initialize the decompression structure
     if((nResult = inflateInit(&z)) == Z_OK)
     {
         // Call zlib to decompress the data
         nResult = inflate(&z, Z_NO_FLUSH);
-        inflateEnd(&z);
+        if (nResult == Z_OK || nResult == Z_STREAM_END)
+        {
+            // Give the size of the uncompressed data
+            cbOutBuffer = z.total_out;
+            nError = ERROR_SUCCESS;
+        }
 
-        // Give the size of the uncompressed data
-        *pcbOutBuffer = z.total_out;
+        inflateEnd(&z);
     }
 
-    // Return an error code
-    return (nResult == Z_OK || nResult == Z_STREAM_END) ? ERROR_SUCCESS : ERROR_FILE_CORRUPT;
+    // Give the caller the number of bytes needed
+    pcbOutBuffer[0] = cbOutBuffer;
+    return nError;
 }