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f48fd68887
This adds "attribute macros" (for lack of better name). So far, we have low-level attributes such as crlf and diff, which are defined in operational terms --- setting or unsetting them on a particular path directly affects what is done to the path. For example, in order to decline diffs or crlf conversions on a binary blob, no diffs on PostScript files, and treat all other files normally, you would have something like these: * diff crlf *.ps !diff proprietary.o !diff !crlf That is fine as the operation goes, but gets unwieldy rather rapidly, when we start adding more low-level attributes that are defined in operational terms. A near-term example of such an attribute would be 'merge-3way' which would control if git should attempt the usual 3-way file-level merge internally, or leave merging to a specialized external program of user's choice. When it is added, we do _not_ want to force the users to update the above to: * diff crlf merge-3way *.ps !diff proprietary.o !diff !crlf !merge-3way The way this patch solves this issue is to realize that the attributes the user is assigning to paths are not defined in terms of operations but in terms of what they are. All of the three low-level attributes usually make sense for most of the files that sane SCM users have git operate on (these files are typically called "text'). Only a few cases, such as binary blob, need exception to decline the "usual treatment given to text files" -- and people mark them as "binary". So this allows the $GIT_DIR/info/alternates and .gitattributes at the toplevel of the project to also specify attributes that assigns other attributes. The syntax is '[attr]' followed by an attribute name followed by a list of attribute names: [attr] binary !diff !crlf !merge-3way When "binary" attribute is set to a path, if the path has not got diff/crlf/merge-3way attribute set or unset by other rules, this rule unsets the three low-level attributes. It is expected that the user level .gitattributes will be expressed mostly in terms of attributes based on what the files are, and the above sample would become like this: (built-in attribute configuration) [attr] binary !diff !crlf !merge-3way * diff crlf merge-3way (project specific .gitattributes) proprietary.o binary (user preference $GIT_DIR/info/attributes) *.ps !diff There are a few caveats. * As described above, you can define these macros only in $GIT_DIR/info/attributes and toplevel .gitattributes. * There is no attempt to detect circular definition of macro attributes, and definitions are evaluated from bottom to top as usual to fill in other attributes that have not yet got values. The following would work as expected: [attr] text diff crlf [attr] ps text !diff *.ps ps while this would most likely not (I haven't tried): [attr] ps text !diff [attr] text diff crlf *.ps ps * When a macro says "[attr] A B !C", saying that a path does not have attribute A does not let you tell anything about attributes B or C. That is, given this: [attr] text diff crlf [attr] ps text !diff *.txt !ps path hello.txt, which would match "*.txt" pattern, would have "ps" attribute set to zero, but that does not make text attribute of hello.txt set to false (nor diff attribute set to true). Signed-off-by: Junio C Hamano <junkio@cox.net>
//////////////////////////////////////////////////////////////// GIT - the stupid content tracker //////////////////////////////////////////////////////////////// "git" can mean anything, depending on your mood. - random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant. - stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang. - "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room. - "goddamn idiotic truckload of sh*t": when it breaks Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals. Git is an Open Source project covered by the GNU General Public License. It was originally written by Linus Torvalds with help of a group of hackers around the net. It is currently maintained by Junio C Hamano. Please read the file INSTALL for installation instructions. See Documentation/tutorial.txt to get started, then see Documentation/everyday.txt for a useful minimum set of commands, and "man git-commandname" for documentation of each command. CVS users may also want to read Documentation/cvs-migration.txt. Many Git online resources are accessible from http://git.or.cz/ including full documentation and Git related tools. The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org. To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at http://marc.theaimsgroup.com/?l=git and other archival sites. The messages titled "A note from the maintainer", "What's in git.git (stable)" and "What's cooking in git.git (topics)" and the discussion following them on the mailing list give a good reference for project status, development direction and remaining tasks.