[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 <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Daniel Barkalow 2005-09-24 23:50:04 -04:00 committed by Junio C Hamano
parent c3bc895c81
commit 7061f5c2c5

View File

@ -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
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.