[PATCH] Update git-clone documentation
[git.git] / git-merge.sh
index 5890c7b..d12a2a9 100755 (executable)
@@ -116,16 +116,37 @@ case "$#,$common" in
        # 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"
+       git-read-tree -u -m $head "$1" &&
+       new_head=$(git-rev-parse --verify "$1^0") &&
+       git-update-ref HEAD "$new_head" "$head" || exit 1
        summary "$1"
        dropsave
        exit 0
        ;;
-1,*)
+1,?*"$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.  See if it is really trivial.
+       echo "Trying really trivial in-index merge..."
+       git-update-index --refresh 2>/dev/null
+       if git-read-tree --trivial -m -u $common $head "$1" &&
+          result_tree=$(git-write-tree)
+       then
+           echo "Wonderful."
+           result_commit=$(
+               echo "$merge_msg" |
+               git-commit-tree $result_tree -p HEAD -p "$1"
+           ) || exit
+           git-update-ref HEAD $result_commit $head
+           summary $result_commit
+           dropsave
+           exit 0
+       fi
+       echo "Nope."
+       ;;
 *)
        # An octopus.  If we can reach all the remote we are up to date.
        up_to_date=t
@@ -215,9 +236,9 @@ then
     do
         parents="$parents -p $remote"
     done
-    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents)
+    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
     echo "Committed merge $result_commit, made by $wt_strategy."
-    echo $result_commit >"$GIT_DIR/HEAD"
+    git-update-ref HEAD $result_commit $head
     summary $result_commit
     dropsave
     exit 0