The callback used with git_attr_foreach.
This callback will be invoked only once per attribute name, even if there are multiple rules for a given file. The highest priority rule will be used.
The attribute name.
The attribute value. May be NULL if the attribute is explicitly set to UNSPECIFIED using the '!' sign.
A user-specified pointer.
0 to continue looping, non-zero to stop. This value will be returned from git_attr_foreach.