From 7061f5c2c5fdde49a952db9dfe09bcfd8b8f9794 Mon Sep 17 00:00:00 2001 From: Daniel Barkalow Date: Sat, 24 Sep 2005 23:50:04 -0400 Subject: [PATCH] Finish documenting trivial merge rules Fix missing symbol explanations, a few incorrect cases, and add two-way merge rules. Signed-off-by: Daniel Barkalow Signed-off-by: Junio C Hamano diff --git a/Documentation/technical/trivial-merge.txt b/Documentation/technical/trivial-merge.txt index b3a9915..24c8410 100644 --- a/Documentation/technical/trivial-merge.txt +++ b/Documentation/technical/trivial-merge.txt @@ -10,6 +10,9 @@ This replaces the index with a different tree, keeping the stat info for entries that don't change, and allowing -u to make the minimum required changes to the working tree to have it match. +Entries marked '+' have stat information. Spaces marked '*' don't +affect the result. + index tree result ----------------------- * (empty) (empty) @@ -20,7 +23,30 @@ required changes to the working tree to have it match. Two-way merge ------------- +It is permitted for the index to lack an entry; this does not prevent +any case from applying. + +If the index exists, it is an error for it not to match either the old +or the result. + +If multiple cases apply, the one used is listed first. + +A result which changes the index is an error if the index is not empty +and not up-to-date. + +Entries marked '+' have stat information. Spaces marked '*' don't +affect the result. + case index old new result + ------------------------------------- + 0/2 (empty) * (empty) (empty) + 1/3 (empty) * new new + 4/5 index+ (empty) (empty) index+ + 6/7 index+ (empty) index index+ + 10 index+ index (empty) (empty) + 14/15 index+ old old index+ + 18/19 index+ old index index+ + 20 index+ index new new Three-way merge --------------- @@ -44,30 +70,28 @@ up-to-date. *empty* means that the tree must not have a directory-file conflict with the entry. -For multiple ancestors or remotes, a '+' means that this case applies -even if only one ancestor or remote fits; normally, all of the -ancestors or remotes must be the same. +For multiple ancestors, a '+' means that this case applies even if +only one ancestor or remote fits; a '^' means all of the ancestors +must be the same. case ancest head remote result ---------------------------------------- 1 (empty)+ (empty) (empty) (empty) 2ALT (empty)+ *empty* remote remote -2ALT (empty)+ *empty* remote remote 2 (empty)^ (empty) remote no merge 3ALT (empty)+ head *empty* head 3 (empty)^ head (empty) no merge 4 (empty)^ head remote no merge 5ALT * head head head -6 ancest^ (empty) (empty) no merge -8ALT ancest (empty) ancest (empty) +6 ancest+ (empty) (empty) no merge +8 ancest^ (empty) ancest no merge 7 ancest+ (empty) remote no merge +10 ancest^ ancest (empty) no merge 9 ancest+ head (empty) no merge -10ALT ancest ancest (empty) (empty) -11 ancest+ head remote no merge 16 anc1/anc2 anc1 anc2 no merge 13 ancest+ head ancest head 14 ancest+ ancest remote remote -14ALT ancest+ ancest remote remote +11 ancest+ head remote no merge Only #2ALT and #3ALT use *empty*, because these are the only cases where there can be conflicts that didn't exist before. Note that we @@ -89,4 +113,9 @@ right. This is a case of a reverted patch (in some direction, maybe multiple times), and the right answer depends on looking at crossings of history or common ancestors of the ancestors. -The status as of Sep 5 is that multiple remotes are not supported \ No newline at end of file +Note that, between #6, #7, #9, and #11, all cases not otherwise +covered are handled in this table. + +For #8 and #10, there is alternative behavior, not currently +implemented, where the result is (empty). As currently implemented, +the automatic merge will generally give this effect. -- cgit v0.10.2-6-g49f6