From: Sverre Hvammen Johansen <hvammen@xxxxxxxxx>
This commit uses the reduced parents instead of the actual
parents specified for selecting the merge strategy when doing
a merge. The recorded parents and the commit message stays
the same.
Some cases where we before needed an octopus strategy may now be
done using a two head strategy.
See the documentation for further details.
Signed-off-by: Sverre Hvammen Johansen <hvammen@xxxxxxxxx>
---
Documentation/git-merge.txt | 20 +++++++++-------
git-merge.sh | 50 ++++++++++++++++++++++++-------------------
2 files changed, 39 insertions(+), 31 deletions(-)
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 9cf761d..845d0ed 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -36,7 +36,7 @@ include::merge-options.txt[]
<remote>::
Other branch head merged into our branch. You need at
least one <remote>. Specifying more than one <remote>
- obviously means you are trying an Octopus.
+ usually means you are trying an Octopus.
include::fast-forward-options.txt[]
@@ -158,11 +158,12 @@ After seeing a conflict, you can do two things:
JOINING MORE THAN TWO HISTORIES
-------------------------------
-More than one remote may be specified on the command line. Those
-remotes are used for selecting the merge startegy and is also used in
-the merge commit message. However, some of these remotes may not be
-independent. Only remotes with independent heads (reduced parents)
-will be recorded in the merge commit object.
+More than one remote may be specified on the command line. Some of
+these remotes may not have independent heads. Git will only use the
+remotes with independent heads (reduced parents) for selecting the
+merge startegy. The reduced parents are the parents recorded in the
+merge commit object. However, the commit message will reflect the
+remotes specified on the command line.
The following shows master and two topic branches. topicB is based
on topicA, topicA is previously branched off from master:
@@ -177,9 +178,10 @@ on topicA, topicA is previously branched off from master:
------------
Merging topicA and topicB to the master branch will select the merge
-strategy based on all three branches (an Octopus). master and topicB
-are the reduced parents and are therefore the only parents recorded in
-the merge commit object:
+strategy based on the two independent branch heads, tip of the master
+branch and the tip of the topicB branch (a two head strategy). The
+commits are also the reduced parents recorded in the merge commit
+object:
------------
diff --git a/git-merge.sh b/git-merge.sh
index fc14c4b..775dae7 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -344,11 +344,16 @@ set x $remoteheads ; shift
find_reduced_parents "$@"
-actual_parents=$(git rev-parse "$@")
+# ff_head may be included here or later in actual parents
+if test -n "$reduced_parents"
+then
+ test $head = $ff_head ||
+ reduced_parents="$ff_head$LF$reduced_parents"
+fi
case "$use_strategies" in
'')
- case "$actual_parents" in
+ case "$reduced_parents" in
?*"$LF"?*)
var="`git config --get pull.octopus`"
if test -n "$var"
@@ -413,17 +418,23 @@ then
finish "$new_head" "$msg" || exit
dropsave
exit 0
+ else
+ reduced_parents="$ff_head"
+ ff_head=$head
fi
+else
+ test $head != $ff_head -a $fast_forward = never &&
+ reduced_parents="$ff_head$LF$reduced_parents"
fi
-case "$actual_parents" in
+case "$reduced_parents" in
?*"$LF"?*)
- # We have more than one actual parent
- common=$(git show-branch --merge-base $head $actual_parents)
+ # We have more than one reduced parent
+ common=$(git show-branch --merge-base $head $reduced_parents)
;;
*)
- # We have exactly one actual parent
- test "$common" != not_queried || common=$(git merge-base --all $head $actual_parents)
+ # We have exactly one reduced parent
+ test "$common" != not_queried || common=$(git merge-base --all $head $reduced_parents)
case "$common" in
?*"$LF"?*)
# We are not doing octopus and not fast forward. Need a
@@ -436,13 +447,13 @@ case "$actual_parents" in
# See if it is really trivial.
git var GIT_COMMITTER_IDENT >/dev/null || exit
echo "Trying really trivial in-index merge..."
- if git read-tree --trivial -m -u -v $common $head $actual_parents &&
+ if git read-tree --trivial -m -u -v $common $head $reduced_parents &&
result_tree=$(git write-tree)
then
echo "Wonderful."
result_commit=$(
printf '%s\n' "$merge_msg" |
- git commit-tree $result_tree -p HEAD -p $actual_parents
+ git commit-tree $result_tree -p HEAD -p $reduced_parents
) || exit
finish "$result_commit" "In-index merge"
dropsave
@@ -491,7 +502,7 @@ do
# Remember which strategy left the state in the working tree
wt_strategy=$strategy
- git-merge-$strategy $common -- "$head_arg" $actual_parents
+ git-merge-$strategy $common -- "$head_arg" $reduced_parents
exit=$?
if test "$no_commit" = t && test "$exit" = 0
then
@@ -527,17 +538,12 @@ done
# auto resolved the merge cleanly.
if test '' != "$result_tree"
then
- if test $fast_forward = allow
- then
- parents=$(git show-branch --independent "$head" "$@")
- else
- parents=$(git rev-parse "$head" "$@")
- fi
- parents=$(echo "$parents" | sed -e 's/^/-p /')
- result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents) || exit
- finish "$result_commit" "Merge made by $wt_strategy."
- dropsave
- exit 0
+ test $head = $ff_head && reduced_parents="$head$LF$reduced_parents"
+ parents=$(echo "$reduced_parents" | sed -e 's/^/-p /')
+ result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents) || exit
+ finish "$result_commit" "Merge made by $wt_strategy."
+ dropsave
+ exit 0
fi
# Pick the result from the best strategy and have the user fix it up.
@@ -561,7 +567,7 @@ case "$best_strategy" in
echo "Rewinding the tree to pristine..."
restorestate
echo "Using the $best_strategy to prepare resolving by hand."
- git-merge-$best_strategy $common -- "$head_arg" $actual_parents
+ git-merge-$best_strategy $common -- "$head_arg" $reduced_parents
;;
esac
--
1.5.5.1.499.g878b8
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