#!/bin/sh # # Copyright (c) 2005 Junio C Hamano # . git-sh-setup || die "Not a git archive" LF=' ' usage () { die "git-merge [-n] [-s ]... +" } # all_strategies='resolve recursive stupid octopus' all_strategies='recursive octopus resolve stupid' default_strategies='resolve octopus' use_strategies= dropsave() { rm -f -- "$GIT_DIR/MERGE_HEAD" \ "$GIT_DIR/MERGE_SAVE" || exit 1 } savestate() { git diff -r -z --name-only $head | cpio -0 -o >"$GIR_DIR/MERGE_SAVE" } restorestate() { git reset --hard $head cpio -iuv <"$GIT_DIR/MERGE_SAVE" git-update-index --refresh >/dev/null } summary() { case "$no_summary" in '') git-diff-tree -p -M $head "$1" | git-apply --stat --summary ;; esac } while case "$#" in 0) break ;; esac do case "$1" in -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\ --no-summa|--no-summar|--no-summary) no_summary=t ;; -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\ --strateg=*|--strategy=*|\ -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy) case "$#,$1" in *,*=*) strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;; 1,*) usage ;; *) strategy="$2" shift ;; esac case " $all_strategies " in *" $strategy "*) use_strategies="$use_strategies$strategy " ;; *) die "available strategies are: $all_strategies" ;; esac ;; -*) usage ;; *) break ;; esac shift done case "$use_strategies" in '') use_strategies=$default_strategies ;; esac test "$#" -le 2 && usage ;# we need at least two heads. merge_msg="$1" shift head_arg="$1" head=$(git-rev-parse --verify "$1"^0) || usage shift # All the rest are remote heads for remote do git-rev-parse --verify "$remote"^0 >/dev/null || die "$remote - not something we can merge" done common=$(git-show-branch --merge-base $head "$@") echo "$head" >"$GIT_DIR/ORIG_HEAD" case "$#,$common" in *,'') die "Unable to find common commit between $head_arg and $*" ;; 1,"$1") # If head can reach all the merge then we are up to date. # but first the most common case of merging one remote echo "Already up-to-date. Yeeah!" dropsave exit 0 ;; 1,"$head") # Again the most common case of merging one remote. echo "Updating from $head to $1." git-update-index --refresh 2>/dev/null git-read-tree -u -m $head "$1" || exit 1 git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD" summary "$1" dropsave exit 0 ;; 1,*) # We are not doing octopus and not fast forward. Need a # real merge. ;; *) # An octopus. If we can reach all the remote we are up to date. up_to_date=t for remote do common_one=$(git-merge-base $head $remote) if test "$common_one" != "$remote" then up_to_date=f break fi done if test "$up_to_date" = t then echo "Already up-to-date. Yeeah!" dropsave exit 0 fi ;; esac # 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 $head commit. files=$(git-diff-index --cached --name-only $head) || exit if [ "$files" ]; then echo >&2 "Dirty index: cannot merge (dirty: $files)" exit 1 fi case "$use_strategies" in ?*' '?*) # Stash away the local changes so that we can try more than one. savestate single_strategy=no ;; *) single_strategy=yes ;; esac result_tree= best_cnt=-1 best_strategy= wt_strategy= 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" "$@" || { # The backend exits with 1 when conflicts are left to be resolved, # with 2 when it does not handle the given merge at all. exit=$? 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="-p $head" for remote do parents="$parents -p $remote" done result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) echo "Committed merge $result_commit, made by $wt_strategy." echo $result_commit >"$GIT_DIR/HEAD" summary $result_commit dropsave exit 0 fi # Pick the result from the best strategy and have the user fix it up. case "$best_strategy" in '') restorestate die "No merge strategy handled the merge." ;; "$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 for remote do echo $remote done >"$GIT_DIR/MERGE_HEAD" die "Automatic merge failed; fix up by hand"