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Diffstat (limited to 'git-merge.sh')
| -rwxr-xr-x | git-merge.sh | 497 |
1 files changed, 497 insertions, 0 deletions
diff --git a/git-merge.sh b/git-merge.sh new file mode 100755 index 0000000000..b2f8a2acd3 --- /dev/null +++ b/git-merge.sh @@ -0,0 +1,497 @@ +#!/bin/sh +# +# Copyright (c) 2005 Junio C Hamano +# + +USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+' + +SUBDIRECTORY_OK=Yes +. git-sh-setup +require_work_tree +cd_to_toplevel + +test -z "$(git ls-files -u)" || + die "You are in the middle of a conflicted merge." + +LF=' +' + +all_strategies='recur recursive octopus resolve stupid ours subtree' +default_twohead_strategies='recursive' +default_octopus_strategies='octopus' +no_trivial_merge_strategies='ours subtree' +use_strategies= + +index_merge=t + +dropsave() { + rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \ + "$GIT_DIR/MERGE_SAVE" || exit 1 +} + +savestate() { + # Stash away any local modifications. + git-diff-index -z --name-only $head | + cpio -0 -o >"$GIT_DIR/MERGE_SAVE" +} + +restorestate() { + if test -f "$GIT_DIR/MERGE_SAVE" + then + git reset --hard $head >/dev/null + cpio -iuv <"$GIT_DIR/MERGE_SAVE" + git-update-index --refresh >/dev/null + fi +} + +finish_up_to_date () { + case "$squash" in + t) + echo "$1 (nothing to squash)" ;; + '') + echo "$1" ;; + esac + dropsave +} + +squash_message () { + echo Squashed commit of the following: + echo + git-log --no-merges ^"$head" $remote +} + +finish () { + if test '' = "$2" + then + rlogm="$GIT_REFLOG_ACTION" + else + echo "$2" + rlogm="$GIT_REFLOG_ACTION: $2" + fi + case "$squash" in + t) + echo "Squash commit -- not updating HEAD" + squash_message >"$GIT_DIR/SQUASH_MSG" + ;; + '') + case "$merge_msg" in + '') + echo "No merge message -- not updating HEAD" + ;; + *) + git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1 + ;; + esac + ;; + esac + case "$1" in + '') + ;; + ?*) + case "$no_summary" in + '') + git-diff-tree --stat --summary -M "$head" "$1" + ;; + esac + ;; + esac +} + +merge_name () { + remote="$1" + rh=$(git-rev-parse --verify "$remote^0" 2>/dev/null) || return + bh=$(git-show-ref -s --verify "refs/heads/$remote" 2>/dev/null) + if test "$rh" = "$bh" + then + echo "$rh branch '$remote' of ." + elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') && + git-show-ref -q --verify "refs/heads/$truname" 2>/dev/null + then + echo "$rh branch '$truname' (early part) of ." + elif test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" + then + sed -e 's/ not-for-merge / /' -e 1q \ + "$GIT_DIR/FETCH_HEAD" + else + echo "$rh commit '$remote'" + fi +} + +case "$#" in 0) usage ;; esac + +have_message= +while case "$#" in 0) break ;; esac +do + case "$1" in + -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\ + --no-summa|--no-summar|--no-summary) + no_summary=t ;; + --sq|--squ|--squa|--squas|--squash) + squash=t no_commit=t ;; + --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit) + no_commit=t ;; + -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\ + --strateg=*|--strategy=*|\ + -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy) + case "$#,$1" in + *,*=*) + strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;; + 1,*) + usage ;; + *) + strategy="$2" + shift ;; + esac + case " $all_strategies " in + *" $strategy "*) + use_strategies="$use_strategies$strategy " ;; + *) + die "available strategies are: $all_strategies" ;; + esac + ;; + -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*) + merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'` + have_message=t + ;; + -m|--m|--me|--mes|--mess|--messa|--messag|--message) + shift + case "$#" in + 1) usage ;; + esac + merge_msg="$1" + have_message=t + ;; + -*) usage ;; + *) break ;; + esac + shift +done + +# This could be traditional "merge <msg> HEAD <commit>..." and the +# way we can tell it is to see if the second token is HEAD, but some +# people might have misused the interface and used a committish that +# is the same as HEAD there instead. Traditional format never would +# have "-m" so it is an additional safety measure to check for it. + +if test -z "$have_message" && + second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) && + head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) && + test "$second_token" = "$head_commit" +then + merge_msg="$1" + shift + head_arg="$1" + shift +elif ! git-rev-parse --verify HEAD >/dev/null 2>&1 +then + # If the merged head is a valid one there is no reason to + # forbid "git merge" into a branch yet to be born. We do + # the same for "git pull". + if test 1 -ne $# + then + echo >&2 "Can merge only exactly one commit into empty head" + exit 1 + fi + + rh=$(git rev-parse --verify "$1^0") || + die "$1 - not something we can merge" + + git-update-ref -m "initial pull" HEAD "$rh" "" && + git-read-tree --reset -u HEAD + exit + +else + # We are invoked directly as the first-class UI. + head_arg=HEAD + + # All the rest are the commits being merged; prepare + # the standard merge summary message to be appended to + # the given message. If remote is invalid we will die + # later in the common codepath so we discard the error + # in this loop. + merge_name=$(for remote + do + merge_name "$remote" + done | git-fmt-merge-msg + ) + merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" +fi +head=$(git-rev-parse --verify "$head_arg"^0) || usage + +# All the rest are remote heads +test "$#" = 0 && usage ;# we need at least one remote head. +set_reflog_action "merge $*" + +remoteheads= +for remote +do + remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) || + die "$remote - not something we can merge" + remoteheads="${remoteheads}$remotehead " + eval GITHEAD_$remotehead='"$remote"' + export GITHEAD_$remotehead +done +set x $remoteheads ; shift + +case "$use_strategies" in +'') + case "$#" in + 1) + var="`git-config --get pull.twohead`" + if test -n "$var" + then + use_strategies="$var" + else + use_strategies="$default_twohead_strategies" + fi ;; + *) + var="`git-config --get pull.octopus`" + if test -n "$var" + then + use_strategies="$var" + else + use_strategies="$default_octopus_strategies" + fi ;; + esac + ;; +esac + +for s in $use_strategies +do + for nt in $no_trivial_merge_strategies + do + case " $s " in + *" $nt "*) + index_merge=f + break + ;; + esac + done +done + +case "$#" in +1) + common=$(git-merge-base --all $head "$@") + ;; +*) + common=$(git-show-branch --merge-base $head "$@") + ;; +esac +echo "$head" >"$GIT_DIR/ORIG_HEAD" + +case "$index_merge,$#,$common,$no_commit" in +f,*) + # We've been told not to try anything clever. Skip to real merge. + ;; +?,*,'',*) + # No common ancestors found. We need a real merge. + ;; +?,1,"$1",*) + # If head can reach all the merge then we are up to date. + # but first the most common case of merging one remote. + finish_up_to_date "Already up-to-date." + exit 0 + ;; +?,1,"$head",*) + # Again the most common case of merging one remote. + echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)" + git-update-index --refresh 2>/dev/null + msg="Fast forward" + if test -n "$have_message" + then + msg="$msg (no commit created; -m option ignored)" + fi + new_head=$(git-rev-parse --verify "$1^0") && + git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" && + finish "$new_head" "$msg" || exit + dropsave + exit 0 + ;; +?,1,?*"$LF"?*,*) + # We are not doing octopus and not fast forward. Need a + # real merge. + ;; +?,1,*,) + # We are not doing octopus, not fast forward, and have only + # one common. + git-update-index --refresh 2>/dev/null + case " $use_strategies " in + *' recursive '*|*' recur '*) + : run merge later + ;; + *) + # 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 "$1" && + result_tree=$(git-write-tree) + then + echo "Wonderful." + result_commit=$( + printf '%s\n' "$merge_msg" | + git-commit-tree $result_tree -p HEAD -p "$1" + ) || exit + finish "$result_commit" "In-index merge" + dropsave + exit 0 + fi + echo "Nope." + esac + ;; +*) + # An octopus. If we can reach all the remote we are up to date. + up_to_date=t + for remote + do + common_one=$(git-merge-base --all $head $remote) + if test "$common_one" != "$remote" + then + up_to_date=f + break + fi + done + if test "$up_to_date" = t + then + finish_up_to_date "Already up-to-date. Yeeah!" + exit 0 + fi + ;; +esac + +# We are going to make a new commit. +git var GIT_COMMITTER_IDENT >/dev/null || exit + +# At this point, we need a real merge. No matter what strategy +# we use, it would operate on the index, possibly affecting the +# working tree, and when resolved cleanly, have the desired tree +# in the index -- this means that the index must be in sync with +# the $head commit. The strategies are responsible to ensure this. + +case "$use_strategies" in +?*' '?*) + # Stash away the local changes so that we can try more than one. + savestate + single_strategy=no + ;; +*) + rm -f "$GIT_DIR/MERGE_SAVE" + single_strategy=yes + ;; +esac + +result_tree= best_cnt=-1 best_strategy= wt_strategy= +merge_was_ok= +for strategy in $use_strategies +do + test "$wt_strategy" = '' || { + echo "Rewinding the tree to pristine..." + restorestate + } + case "$single_strategy" in + no) + echo "Trying merge strategy $strategy..." + ;; + esac + + # Remember which strategy left the state in the working tree + wt_strategy=$strategy + + git-merge-$strategy $common -- "$head_arg" "$@" + exit=$? + if test "$no_commit" = t && test "$exit" = 0 + then + merge_was_ok=t + exit=1 ;# pretend it left conflicts. + fi + + test "$exit" = 0 || { + + # The backend exits with 1 when conflicts are left to be resolved, + # with 2 when it does not handle the given merge at all. + + if test "$exit" -eq 1 + then + cnt=`{ + git-diff-files --name-only + git-ls-files --unmerged + } | wc -l` + if test $best_cnt -le 0 -o $cnt -le $best_cnt + then + best_strategy=$strategy + best_cnt=$cnt + fi + fi + continue + } + + # Automerge succeeded. + result_tree=$(git-write-tree) && break +done + +# If we have a resulting tree, that means the strategy module +# auto resolved the merge cleanly. +if test '' != "$result_tree" +then + parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /') + result_commit=$(printf '%s\n' "$merge_msg" | git-commit-tree $result_tree $parents) || exit + finish "$result_commit" "Merge made by $wt_strategy." + dropsave + exit 0 +fi + +# Pick the result from the best strategy and have the user fix it up. +case "$best_strategy" in +'') + restorestate + case "$use_strategies" in + ?*' '?*) + echo >&2 "No merge strategy handled the merge." + ;; + *) + echo >&2 "Merge with strategy $use_strategies failed." + ;; + esac + exit 2 + ;; +"$wt_strategy") + # We already have its result in the working tree. + ;; +*) + echo "Rewinding the tree to pristine..." + restorestate + echo "Using the $best_strategy to prepare resolving by hand." + git-merge-$best_strategy $common -- "$head_arg" "$@" + ;; +esac + +if test "$squash" = t +then + finish +else + for remote + do + echo $remote + done >"$GIT_DIR/MERGE_HEAD" + printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" +fi + +if test "$merge_was_ok" = t +then + echo >&2 \ + "Automatic merge went well; stopped before committing as requested" + exit 0 +else + { + echo ' +Conflicts: +' + git ls-files --unmerged | + sed -e 's/^[^ ]* / /' | + uniq + } >>"$GIT_DIR/MERGE_MSG" + if test -d "$GIT_DIR/rr-cache" + then + git-rerere + fi + die "Automatic merge failed; fix conflicts and then commit the result." +fi |