>2Gb of memory used for decoding ~1kb file

[Shnatsel]

The attached files, most of which are under 1Kb in size, require more than 2Gb of RAM to decode. Worse, this occurs in an allocation internal to the code - this memory will be consumed even if the client code uses 4Kb buffers.

Sample files triggering the issue: lz4-fear-decode-ooms.zip

The code to reproduce the issue can be found in #5

[Shnatsel]

The smallest sample triggering the issue is just 20 bytes.