Support '|' in path

[Arkaeriit]

Using '|' as the data separator caused crashes if
a path with a '|' char in it was in the data file. Changing that separator to a null byte ensures
that this kind of issue can never happen again as
the null byte can't be in a path.

[Arkaeriit]

I rebased the branch onto master.

[skywind3000]

The original format is compatible with z.sh, I believe a lot of users may benefit from this PR,
before it get merged there are still some problems to deal with:

1. after the upgrading, will the old history data corrupt ?
2. if users have no idea about this upgrading (just run a clink update *), will they find all of they history data have been lost ?

Some possible options:

1. make the separator configurable ? (via a environment variable), when people are changing it they know what they are doing.
2. make some header in the new format so z.lua can figure out (maybe a "\0\0" marker in the first line) if it is a new format, if not it will convert the old format into the new one ?
3. what about a binary format ?

[Arkaeriit]

Thanks for the feedback. I didn't thought about migration so I definitively need to fix that. Option 2 seems the most sensible to me so I will go with it.

[Arkaeriit]

Turns out changing the separator is not needed. Improving the reading function is enough to fix the bugs and crashes with pipes in filenames.

[skywind3000]

I like this solution, no need to convert the old data, the second argument of string:split() function can specify maximum split items:

z.lua/z.lua

Lines 138 to 152 in 3022099

	function string:split(sSeparator, nMax, bRegexp)
	assert(sSeparator ~= '')
	assert(nMax == nil or nMax >= 1)
	local aRecord = {}
	if self:len() > 0 then
	local bPlain = not bRegexp
	nMax = nMax or -1
	local nField, nStart = 1, 1
	local nFirst, nLast = self:find(sSeparator, nStart, bPlain)
	while nFirst and nMax ~= 0 do
	aRecord[nField] = self:sub(nStart, nFirst - 1)
	nField = nField + 1
	nStart = nLast + 1
	nFirst, nLast = self:find(sSeparator, nStart, bPlain)
	nMax = nMax - 1

is it enough to just use

local part = string.split(line, '|', 3)

??

[Arkaeriit]

Using the second argument of the split function merges the not split part at the end of the input and not at the start like we want.

line = "path|with|a|lot|of|pipes|1212|9999"
line:split("|", 3)) --> {"path", "with", "a", "lot|of|pipes|1212|9999"}

[skywind3000]

got it, thank you for this PR