Snappy.maxCompressedLength can return a negative size

[bersprockets]

This is applicable to snappy-java-1.1.10.7.jar.

bash-3.2$ jshell --class-path /Users/<redacted>/jars/snappy-java-1.1.10.7.jar
|  Welcome to JShell -- Version 21.0.6
|  For an introduction type: /help intro

jshell> import org.xerial.snappy.Snappy;
import org.xerial.snappy.Snappy;

jshell> Snappy.maxCompressedLength(1840700246);
Snappy.maxCompressedLength(1840700246);
$2 ==> -2147483644

jshell> 

This could very well be an appropriate response. But I wanted to verify before I file an issue with a second library which assumes that the result of Snappy.maxCompressedLength is always usable as a buffer size.

[bersprockets]

This seems to be an interaction between the underlying native code and the Java's lack of unsigned integer. The code does this calculation, where source_bytes has the size_t type:

return 32 + source_bytes + source_bytes / 6;

When source_bytes is 1840700246, the result of that calculation is 2147483652 (or 0x80000004). When cast to an int, this ends up as -2147483644.