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The "trivial merge" codepath wants to optimize itself by making an internal call to the read-tree machinery, but it does not read the index before doing so, and the codepath is never exercised. Incidentally, this failure to read the index upfront means that the safety to refuse doing anything when the index is unmerged does not kick in, either. These two problem are fixed by using read_cache_unmerged() that does read the index before checking if it is unmerged at the beginning of cmd_merge(). The primary logic of the merge, however, assumes that the process never reads the index in-core, and the call to write_cache_as_tree() it makes from write_tree_trivial() will always read from the on-disk index that is prepared the strategy back-ends. This assumption is now broken by the above fix. To fix this issue, we now call discard_cache() before calling write_tree_trivial() when it wants to write the on-disk index as a tree. When multiple strategies are tried, their results are evaluated by reading the resulting index and inspecting it. The codepath needs to make a call to read_cache() for each successful strategy, and for that to work, they need to discard_cache() the one read by the previous round. Also the "trivial merge" forgot that the current commit is one of the parents of the resulting commit. Signed-off-by: Junio C Hamano <gitster@pobox.com>
//////////////////////////////////////////////////////////////// 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.