Strip carriage returns from lines in settingtypes.txt

[neoh4x0r]

Fixes issue #11327
Carriage returns should be stripped when reading lines from settingstypes.txt.

Example of Biofuel's settingtypes.txt file cause the problem:
https://github.com/Lokrates/Biofuel/blob/master/settingtypes.txt

2021-06-09 08:18:04: ERROR[Main]: Invalid integer setting in /home/sfence/.minetest/mods/biofuel/settingtypes.txt "fuel_production_time (fuel production time) i"t 10 5 360
2021-06-09 08:18:04: ERROR[Main]: Invalid integer setting in /home/sfence/.minet"st/mods/biofuel/settingtypes.txt "biomass_input (required input) int 4 1 99
2021-06-09 08:18:04: ERROR[Main]: Invalid boolean setting in /home/sfence/.minet"st/mods/biofuel/settingtypes.txt "refinery_output (bottle output) bool false
2021-06-09 08:18:04: ERROR[Main]: Invalid boolean setting in /home/sfence/.minet"st/mods/biofuel/settingtypes.txt "food_fuel (food waste) bool false

Linux uses LF (0x0A, /n) for line endings, but windows uses CRLF (0x0D0A, /r/n).
Lua strips the LF (which is fine on linux, if only using LF), but when the file uses CRLF, the CR gets left behind.

I suspect that when this happens on a windows system -- lua will strip the CRLF completely.

The best solution (cross-platform) is just to remove any stray carriage returns.

[rubenwardy]

I don't get why *line doesn't already handle \r\n correctly, I guess it's not written in a truly platform independent way

Edit:

So, Lua's file:read("*line") uses setvbuf with a mode of _IOLBF to read lines. Not sure what the behaviour of this is exactly

Lua's io.lines([file]) uses a custom implementation that only looks for \n

Yay, consistency

I wonder if it worth having our own iterator to go over lines, and looking for other instances of *line and io.lines()

[rubenwardy]

Surprisingly, this is the only place that manually handles reading lines in the Lua builtin. So I'm fine with this fix

Ideally, this should be fixed in the Lua API as it's complete nonsense that the lines iterator doesn't support \r\n