patch[TOPGIT] make creating a commit from a topgit branch a function

diff --git a/tg-remote.sh b/tg-remote.sh
index c3e8bd3..7f7a1b0 100644
--- a/tg-remote.sh
+++ b/tg-remote.sh
@@ -27,9 +27,9 @@ git config "remote.$name.url" >/dev/null || die "unknown remote '$name'"
 
 ## Configure the remote
 
-git config --add "remote.$name.fetch" "+refs/top-bases/*:refs/remotes/$name/top-bases/*"
-git config --add "remote.$name.push" "+refs/top-bases/*:refs/top-bases/*"
-git config --add "remote.$name.push" "+refs/heads/*:refs/heads/*"
+git config --replace-all "remote.$name.fetch" "+refs/top-bases/*:refs/remotes/$name/top-bases/*" "+refs/top-bases/*:refs/remotes/$name/top-bases/*"
+git config --replace-all "remote.$name.push" "+refs/top-bases/*:refs/top-bases/*" "+refs/top-bases/*:refs/top-bases/*"
+git config --replace-all "remote.$name.push" "+refs/heads/*:refs/heads/*" "+refs/heads/*:refs/heads/*"
 
 info "Remote $name can now follow TopGit topic branches."
 if [ -z "$populate" ]; then

diff --git a/tg-export.sh b/tg-export.sh
index 9e6940f..dea24d9 100644
--- a/tg-export.sh
+++ b/tg-export.sh
@@ -71,14 +71,11 @@ pretty_tree()
 	 git write-tree)
 }
 
-# collapsed_commit NAME
-# Produce a collapsed commit of branch NAME.
-collapsed_commit()
+create_tg_commit()
 {
 	name="$1"
-
-	rm -f "$playground/^pre" "$playground/^post"
-	>"$playground/^body"
+	tree="$2"
+	parent="$3"
 
 	# Get commit message and authorship information
 	git cat-file blob "$name:.topmsg" | git mailinfo "$playground/^msg" /dev/null > "$playground/^info"
@@ -92,6 +89,20 @@ collapsed_commit()
 	test -n "$GIT_AUTHOR_EMAIL" && export GIT_AUTHOR_EMAIL
 	test -n "$GIT_AUTHOR_DATE" && export GIT_AUTHOR_DATE
 
+	(printf '%s\n\n' "$SUBJECT"; cat "$playground/^msg") |
+	git stripspace |
+	git commit-tree "$tree" -p "$parent"
+}
+
+# collapsed_commit NAME
+# Produce a collapsed commit of branch NAME.
+collapsed_commit()
+{
+	name="$1"
+
+	rm -f "$playground/^pre" "$playground/^post"
+	>"$playground/^body"
+
 	# Determine parent
 	parent="$(cut -f 1 "$playground/$name^parents")"
 	if [ "$(cat "$playground/$name^parents" | wc -l)" -gt 1 ]; then
@@ -107,9 +118,7 @@ collapsed_commit()
 	if branch_empty "$name"; then
 		echo "$parent";
 	else
-		(printf '%s\n\n' "$SUBJECT"; cat "$playground/^msg") |
-		git stripspace |
-		git commit-tree "$(pretty_tree "$name")" -p "$parent"
+		create_tg_commit "$name" "$(pretty_tree $name)" "$parent"
 	fi;
 
 	echo "$name" >>"$playground/^ticker"