Implemented manual packfile switching in fast-import.
[gitweb.git] / git-merge.sh
index af1f25b3c51d197ea5fd24b7623dfb591f867133..3eef048efc7a848145697e205d154c92f8c7ec0f 100755 (executable)
@@ -3,24 +3,25 @@
 # Copyright (c) 2005 Junio C Hamano
 #
 
+USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+'
 
-USAGE='[-n] [--no-commit] [-s <strategy>]... <merge-message> <head> <remote>+'
 . git-sh-setup
+set_reflog_action "merge $*"
+require_work_tree
+
+test -z "$(git ls-files -u)" ||
+       die "You are in a middle of conflicted merge."
 
 LF='
 '
 
-all_strategies='recursive octopus resolve stupid ours'
+all_strategies='recur recursive octopus resolve stupid ours'
 default_twohead_strategies='recursive'
 default_octopus_strategies='octopus'
 no_trivial_merge_strategies='ours'
 use_strategies=
 
 index_merge=t
-if test "@@NO_PYTHON@@"; then
-       all_strategies='resolve octopus stupid ours'
-       default_twohead_strategies='resolve'
-fi
 
 dropsave() {
        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
@@ -36,36 +37,92 @@ savestate() {
 restorestate() {
         if test -f "$GIT_DIR/MERGE_SAVE"
        then
-               git reset --hard $head
+               git reset --hard $head >/dev/null
                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
                git-update-index --refresh >/dev/null
        fi
 }
 
-finish () {
-       test '' = "$2" || echo "$2"
-       case "$merge_msg" in
+finish_up_to_date () {
+       case "$squash" in
+       t)
+               echo "$1 (nothing to squash)" ;;
        '')
-               echo "No merge message -- not updating HEAD"
+               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"
                ;;
-       *)
-               git-update-ref HEAD "$1" "$head" || exit 1
+       '')
+               case "$merge_msg" in
+               '')
+                       echo "No merge message -- not updating HEAD"
+                       ;;
+               *)
+                       git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
+                       ;;
+               esac
                ;;
        esac
-
-       case "$no_summary" in
+       case "$1" in
        '')
-               git-diff-tree -p --stat --summary -M "$head" "$1"
+               ;;
+       ?*)
+               case "$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 ."
+       else
+               echo "$rh               commit '$remote'"
+       fi
+}
+
+case "$#" in 0) usage ;; esac
+
+have_message=
 while case "$#" in 0) break ;; esac
 do
        case "$1" in
        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
                --no-summa|--no-summar|--no-summary)
                no_summary=t ;;
+       --sq|--squ|--squa|--squas|--squash)
+               squash=t no_commit=t ;;
        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
                no_commit=t ;;
        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
@@ -73,7 +130,7 @@ do
        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
                case "$#,$1" in
                *,*=*)
-                       strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
+                       strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
                1,*)
                        usage ;;
                *)
@@ -87,17 +144,74 @@ do
                        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
 
-merge_msg="$1"
-shift
-head_arg="$1"
-head=$(git-rev-parse --verify "$1"^0) || usage
-shift
+# This could be traditional "merge <msg> HEAD <commit>..."  and the
+# way we can tell it is to see if the second token is HEAD, but some
+# people might have misused the interface and used a committish that
+# is the same as HEAD there instead.  Traditional format never would
+# have "-m" so it is an additional safety measure to check for it.
+
+if test -z "$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 "$#" = 0 && usage ;# we need at least one remote head.
@@ -105,9 +219,11 @@ test "$#" = 0 && usage ;# we need at least one remote head.
 remoteheads=
 for remote
 do
-       remotehead=$(git-rev-parse --verify "$remote"^0) ||
+       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
 
@@ -115,9 +231,21 @@ case "$use_strategies" in
 '')
        case "$#" in
        1)
-               use_strategies="$default_twohead_strategies" ;;
+               var="`git-repo-config --get pull.twohead`"
+               if test -n "$var"
+               then
+                       use_strategies="$var"
+               else
+                       use_strategies="$default_twohead_strategies"
+               fi ;;
        *)
-               use_strategies="$default_octopus_strategies" ;;
+               var="`git-repo-config --get pull.octopus`"
+               if test -n "$var"
+               then
+                       use_strategies="$var"
+               else
+                       use_strategies="$default_octopus_strategies"
+               fi ;;
        esac
        ;;
 esac
@@ -152,16 +280,15 @@ f,*)
 ?,1,"$1",*)
        # If head can reach all the merge then we are up to date.
        # but first the most common case of merging one remote.
-       echo "Already up-to-date."
-       dropsave
+       finish_up_to_date "Already up-to-date."
        exit 0
        ;;
 ?,1,"$head",*)
        # Again the most common case of merging one remote.
-       echo "Updating from $head to $1"
+       echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
        git-update-index --refresh 2>/dev/null
        new_head=$(git-rev-parse --verify "$1^0") &&
-       git-read-tree -u -v -m $head "$new_head" &&
+       git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
        finish "$new_head" "Fast forward"
        dropsave
        exit 0
@@ -205,8 +332,7 @@ f,*)
        done
        if test "$up_to_date" = t
        then
-               echo "Already up-to-date. Yeeah!"
-               dropsave
+               finish_up_to_date "Already up-to-date. Yeeah!"
                exit 0
        fi
        ;;
@@ -288,7 +414,7 @@ if test '' != "$result_tree"
 then
     parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
     result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
-    finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
+    finish "$result_commit" "Merge made by $wt_strategy."
     dropsave
     exit 0
 fi
@@ -297,7 +423,14 @@ fi
 case "$best_strategy" in
 '')
        restorestate
-       echo >&2 "No merge strategy handled the merge."
+       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")
@@ -310,11 +443,17 @@ case "$best_strategy" in
        git-merge-$best_strategy $common -- "$head_arg" "$@"
        ;;
 esac
-for remote
-do
-       echo $remote
-done >"$GIT_DIR/MERGE_HEAD"
-echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
+
+if test "$squash" = t
+then
+       finish
+else
+       for remote
+       do
+               echo $remote
+       done >"$GIT_DIR/MERGE_HEAD"
+       echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
+fi
 
 if test "$merge_was_ok" = t
 then