MySQL Bugs: #47190: [Corner case] Proxy crashes on windows if proxy-lua-script is a folder

Bug #47190	[Corner case] Proxy crashes on windows if proxy-lua-script is a folder
Submitted:	8 Sep 16:47	Modified:	8 Sep 17:03
Reporter:	Diego Medina
Status:	Verified
Category:	Proxy: Core	Severity:	S3 (Non-critical)
Version:	0.8.0	OS:	Microsoft Windows
Assigned to:	MEM Agent Devs	Target Version:

Description:
Windows only.

If you specify a folder, instead of a lua script to --proxy-lua-script= , as soon as you
connect through the proxy port, it will crash.

This also happens if you add a /  to the name of your lua script (like a typo)

The error you get is:
..\src\lua-load-factory.c:86:???: assertion failed (NULL != factoruy->data.file.f)

How to repeat:
1- Start the proxy on windows like this:

c:\mysql-proxy\bin\mysql-proxy.exe --proxy-lua-sctip=c:\boot.ini\

2- on a new terminal, connect to the proxy port and notice the error message on the
terminal that started the proxy.

Note, the file has to exist. if you specify a non-existing file or folder, the proxy will
not crash.

Note2: boot.ini if of course not a lua script, so if you want, just replace that for a
lua script :)

Suggested fix:
Log an error instead of crashing.

Kay Roepke writes: 
The code probably only needs some path cleansing and additional error checking.