diff options
Diffstat (limited to 'contrib')
| -rwxr-xr-x | contrib/examples/git-merge.sh | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/contrib/examples/git-merge.sh b/contrib/examples/git-merge.sh new file mode 100755 index 0000000000..8026ccff4a --- /dev/null +++ b/contrib/examples/git-merge.sh @@ -0,0 +1,554 @@ +#!/bin/sh +# +# Copyright (c) 2005 Junio C Hamano +# + +OPTIONS_KEEPDASHDASH= +OPTIONS_SPEC="\ +git-merge [options] <remote>... +git-merge [options] <msg> HEAD <remote> +-- +stat show a diffstat at the end of the merge +n don't show a diffstat at the end of the merge +summary (synonym to --stat) +log add list of one-line log to merge commit message +squash create a single commit instead of doing a merge +commit perform a commit if the merge succeeds (default) +ff allow fast forward (default) +s,strategy= merge strategy to use +m,message= message to be used for the merge commit (if any) +" + +SUBDIRECTORY_OK=Yes +. git-sh-setup +require_work_tree +cd_to_toplevel + +test -z "$(git ls-files -u)" || + die "You are in the middle of a conflicted merge." + +LF=' +' + +all_strategies='recur recursive octopus resolve stupid ours subtree' +default_twohead_strategies='recursive' +default_octopus_strategies='octopus' +no_fast_forward_strategies='subtree ours' +no_trivial_strategies='recursive recur subtree ours' +use_strategies= + +allow_fast_forward=t +allow_trivial_merge=t +squash= no_commit= log_arg= + +dropsave() { + rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \ + "$GIT_DIR/MERGE_STASH" || exit 1 +} + +savestate() { + # Stash away any local modifications. + git stash create >"$GIT_DIR/MERGE_STASH" +} + +restorestate() { + if test -f "$GIT_DIR/MERGE_STASH" + then + git reset --hard $head >/dev/null + git stash apply $(cat "$GIT_DIR/MERGE_STASH") + git update-index --refresh >/dev/null + fi +} + +finish_up_to_date () { + case "$squash" in + t) + echo "$1 (nothing to squash)" ;; + '') + echo "$1" ;; + esac + dropsave +} + +squash_message () { + echo Squashed commit of the following: + echo + git log --no-merges --pretty=medium ^"$head" $remoteheads +} + +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 + git gc --auto + ;; + esac + ;; + esac + case "$1" in + '') + ;; + ?*) + if test "$show_diffstat" = t + then + # We want color (if set), but no pager + GIT_PAGER='' git diff --stat --summary -M "$head" "$1" + fi + ;; + esac + + # Run a post-merge hook + if test -x "$GIT_DIR"/hooks/post-merge + then + case "$squash" in + t) + "$GIT_DIR"/hooks/post-merge 1 + ;; + '') + "$GIT_DIR"/hooks/post-merge 0 + ;; + esac + fi +} + +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 +} + +parse_config () { + while test $# != 0; do + case "$1" in + -n|--no-stat|--no-summary) + show_diffstat=false ;; + --stat|--summary) + show_diffstat=t ;; + --log|--no-log) + log_arg=$1 ;; + --squash) + test "$allow_fast_forward" = t || + die "You cannot combine --squash with --no-ff." + squash=t no_commit=t ;; + --no-squash) + squash= no_commit= ;; + --commit) + no_commit= ;; + --no-commit) + no_commit=t ;; + --ff) + allow_fast_forward=t ;; + --no-ff) + test "$squash" != t || + die "You cannot combine --squash with --no-ff." + allow_fast_forward=f ;; + -s|--strategy) + shift + case " $all_strategies " in + *" $1 "*) + use_strategies="$use_strategies$1 " ;; + *) + die "available strategies are: $all_strategies" ;; + esac + ;; + -m|--message) + shift + merge_msg="$1" + have_message=t + ;; + --) + shift + break ;; + *) usage ;; + esac + shift + done + args_left=$# +} + +test $# != 0 || usage + +have_message= + +if branch=$(git-symbolic-ref -q HEAD) +then + mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") + if test -n "$mergeopts" + then + parse_config $mergeopts -- + fi +fi + +parse_config "$@" +while test $args_left -lt $#; do shift; done + +if test -z "$show_diffstat"; then + test "$(git config --bool merge.diffstat)" = false && show_diffstat=false + test "$(git config --bool merge.stat)" = false && show_diffstat=false + test -z "$show_diffstat" && show_diffstat=t +fi + +# This could be traditional "merge <msg> HEAD <commit>..." and the +# way we can tell it is to see if the second token is HEAD, but some +# people might have misused the interface and used a committish that +# is the same as HEAD there instead. Traditional format never would +# have "-m" so it is an additional safety measure to check for it. + +if test -z "$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 $log_arg + ) + merge_msg="${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 ss in $no_fast_forward_strategies + do + case " $s " in + *" $ss "*) + allow_fast_forward=f + break + ;; + esac + done + for ss in $no_trivial_strategies + do + case " $s " in + *" $ss "*) + allow_trivial_merge=f + break + ;; + esac + done +done + +case "$#" in +1) + common=$(git merge-base --all $head "$@") + ;; +*) + common=$(git show-branch --merge-base $head "$@") + ;; +esac +echo "$head" >"$GIT_DIR/ORIG_HEAD" + +case "$allow_fast_forward,$#,$common,$no_commit" in +?,*,'',*) + # No common ancestors found. We need a real merge. + ;; +?,1,"$1",*) + # If head can reach all the merge then we are up to date. + # but first the most common case of merging one remote. + finish_up_to_date "Already up-to-date." + exit 0 + ;; +t,1,"$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,?*"$LF"?*,*) + # We are not doing octopus and not fast forward. Need a + # real merge. + ;; +?,1,*,) + # We are not doing octopus, not fast forward, and have only + # one common. + git update-index --refresh 2>/dev/null + case "$allow_trivial_merge" in + t) + # 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_STASH" + 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 '' != "$result_tree" +then + if test "$allow_fast_forward" = "t" + 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 $wt_strategy." + dropsave + exit 0 +fi + +# Pick the result from the best strategy and have the user fix it up. +case "$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" + git rerere + die "Automatic merge failed; fix conflicts and then commit the result." +fi |