Re: [PATCH] Document disabling core.whitespace values trailing-space and space-before-tab
From: Peter Valdemar Mørch (Lists) <hidden>
Date: 2016-06-15 22:45:00
Actually, it gets stranger and stranger! Nanako Shiraishi nanako3-at-lavabit.com |Lists| wrote:
quoted
The '-trailing-space' syntax to disable the trailing-space setting is not obvious and not documented as far as I can see. I would have assumed a value of '' would disable it.Doesn't gitattributes(5) describe the overall syntax in detail?
First, git-config.1 does not mention gitattributes except for specific settings. core.whitespace is not one of these. gitattributes.5 has:
Sometimes you would need to override an setting of an attribute for a path to unspecified state. This can be done by listing the name of the attribute prefixed with an exclamation point !.
note that this is ! before the *name* of the attribute, and for "Checking whitespace errors / whitespace":
The core.whitespace configuration variable allows you to define what diff and apply should consider whitespace errors for all paths in the project (See git-config(1)). This attribute gives you finer control per path.
...
Unspecified: Use the value of core.whitespace configuration variable to decide what to notice as error. String: Specify a comma separate list of common whitespace problems to notice in the same format as core.whitespace configuration variable.
So now, git attributes says to unspecify a setting with '!' in front of the attribute *name*, which for core.whitespace means use the value from git-config, which if not specified means to error on e.g. trailing-space. Now, I notice that git's own .gitattributes has this:
* whitespace=!indent,trail,space *.[ch] whitespace
Which I assume actually works, but is invalid according to git-config.1 and gitattributes.5 because: For the first line, neither of the values 'indent', 'trail' nor 'space' are valid for core.whitespace, and the '!' notation is not defined in neither gitattributes.5 nor in git-config.1 for *values*. For the second line, gitattributes states generally about attributes that:
Set: The path has the attribute with special value "true"; this is specified by listing only the name of the attribute in the attribute list.
A value of true (unspecified would have required:"*.[ch] !whitespace") is not valid for core.whitespace either. So now (as I read it), neither git-config.1 nor gitattributes.5 specify how to turn off core.whitespace "elements", but .gitattributes (from git itself) uses one notation (!) with settings that are invalid for other reaons, while "grep core.whitespace t/*" uses another notation (-) to turn off elements. Also in t/* the elements have various different names, such as: "trail", "trailing", "trailing-space". t/t4019-diff-wserror.sh also uses this:
echo "F whitespace=-trail" >.gitattributes
just to make things interesting! It seems that there is some inconsistency about this. Perhaps documentation (and changing t/* and .gitattributes accordingly) isn't such a bad idea! :D Peter -- Peter Valdemar Mørch http://www.morch.com