Consistent message encoding while reusing log from an existing commit.

The following commands can reuse log message from an existing
commit while creating a new commit:

	git-cherry-pick
	git-rebase (both with and without --merge)
	git-commit (-c and -C)

When the original commit was made in a different encoding from
the current i18n.commitencoding, "cat-file commit" would give a
string that is inconsistent with what the resulting commit will
claim to be in.  Replace them with "git show -s --encoding".

"git-rebase" without --merge is "git format-patch" piped to "git
am" in essence, and has been taken care of before this commit.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-commit.sh

@@ -435,7 +435,9 @@ then
 	fi
 elif test "$use_commit" != ""
 then
-	git-cat-file commit "$use_commit" | sed -e '1,/^$/d'
+	encoding=$(git repo-config i18n.commitencoding || echo UTF-8)
+	git show -s --pretty=raw --encoding="$encoding" "$use_commit" |
+	sed -e '1,/^$/d' -e 's/^    //'
 elif test -f "$GIT_DIR/MERGE_MSG"
 then
 	cat "$GIT_DIR/MERGE_MSG"
@@ -497,7 +499,8 @@ then
 		q
 	}
 	'
-	set_author_env=`git-cat-file commit "$use_commit" |
+	encoding=$(git repo-config i18n.commitencoding || echo UTF-8)
+	set_author_env=`git show -s --pretty=raw --encoding="$encoding" "$use_commit" |
 	LANG=C LC_ALL=C sed -ne "$pick_author_script"`
 	eval "$set_author_env"
 	export GIT_AUTHOR_NAME

git-revert.sh

@@ -78,17 +78,20 @@ prev=$(git-rev-parse --verify "$commit^1" 2>/dev/null) ||
 git-rev-parse --verify "$commit^2" >/dev/null 2>&1 &&
 	die "Cannot run $me a multi-parent commit."
 
+encoding=$(git repo-config i18n.commitencoding || echo UTF-8)
+
 # "commit" is an existing commit.  We would want to apply
 # the difference it introduces since its first parent "prev"
 # on top of the current HEAD if we are cherry-pick.  Or the
 # reverse of it if we are revert.
 
 case "$me" in
 revert)
-	git-rev-list --pretty=oneline --max-count=1 $commit |
+	git show -s --pretty=oneline --encoding="$encoding" $commit |
 	sed -e '
 		s/^[^ ]* /Revert "/
-		s/$/"/'
+		s/$/"/
+	'
 	echo
 	echo "This reverts commit $commit."
 	test "$rev" = "$commit" ||
@@ -117,14 +120,17 @@ cherry-pick)
 
 		q
 	}'
-	set_author_env=`git-cat-file commit "$commit" |
+
+	logmsg=`git show -s --pretty=raw --encoding="$encoding" "$commit"`
+	set_author_env=`echo "$logmsg" |
 	LANG=C LC_ALL=C sed -ne "$pick_author_script"`
 	eval "$set_author_env"
 	export GIT_AUTHOR_NAME
 	export GIT_AUTHOR_EMAIL
 	export GIT_AUTHOR_DATE
 
-	git-cat-file commit $commit | sed -e '1,/^$/d'
+	echo "$logmsg" |
+	sed -e '1,/^$/d' -e 's/^    //'
 	case "$replay" in
 	'')
 		echo "(cherry picked from commit $commit)"