Fix possible decompression loop when dealing with corrupt data

Summary: We're seeing a case where a file with known data corruption issues can block record decoding, triggering an infinite loop, where no data is read from disk, but no data is extracted from the decompressor either. This case is now caught by this new check.

Reviewed By: maxouellet

Differential Revision: D50828445

fbshipit-source-id: cf8ba13a4e58e1b88282eab66c8bc9913a5f05ce

vrs/RecordReaders.cpp

@@ -83,6 +83,7 @@ int CompressedRecordReader::read(
     uint32_t& outReadSize) {
   outReadSize = 0;
   do {
+    bool readData = false;
     if (decompressor_.getRemainingCompressedDataBufferSize() == 0 && remainingDiskBytes_ > 0) {
       size_t targetReadSize = (knownNeedSize - outReadSize >= remainingUncompressedSize_)
           ? remainingDiskBytes_
@@ -100,6 +101,7 @@ int CompressedRecordReader::read(
       if (error != 0) {
         return error;
       }
+      readData = true;
     }
     uint32_t decompressedSize = 0;
     int error = decompressor_.decompress(
@@ -109,6 +111,9 @@ int CompressedRecordReader::read(
     if (error != 0) {
       return error;
     }
+    if (!readData && decompressedSize == 0) {
+      return NOT_ENOUGH_DATA;
+    }
   } while (outReadSize < destSize);
   return 0;
 }