[TopGit PATCH 04/11] tg-path: use pretty_tree and diff-tree to generate the patch

[Bert Wesarg <bert.wesarg@googlemail.com>]

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
---
 tg-patch.sh |   55 +++++++++++++++++++++++++++++++------------------------
 1 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/tg-patch.sh b/tg-patch.sh
index 5b7386a..9def6e5 100644 tg-patch.sh
--- a/tg-patch.sh
+++ b/tg-patch.sh
@@ -6,8 +6,6 @@
 name=
 
 head_from=
-diff_opts=
-diff_committed_only=yes	# will be unset for index/worktree
 
 
 ## Parse options
@@ -15,15 +13,9 @@ diff_committed_only=yes	# will be unset for index/worktree
 while [ -n "$1" ]; do
 	arg="$1"; shift
 	case "$arg" in
-	-i)
+	-i|-w)
 		[ -z "$head_from" ] || die "-i and -w are mutually exclusive"
-		head_from=-i
-		diff_opts="$diff_opts --cached";
-		diff_committed_only=;;
-	-w)
-		[ -z "$head_from" ] || die "-i and -w are mutually exclusive"
-		head_from=-w
-		diff_committed_only=;;
+		head_from="$arg";;
 	-*)
 		echo "Usage: tg [...] patch [-i | -w] [NAME]" >&2
 		exit 1;;
@@ -49,22 +41,37 @@ fi
 
 setup_pager
 
-cat_file "$name:.topmsg" $head_from
-echo
-[ -n "$(git grep $diff_opts '^[-]--' ${diff_committed_only:+"$name"} -- ".topmsg")" ] || echo '---'
-
-# Evil obnoxious hack to work around the lack of git diff --exclude
-git_is_stupid="$(mktemp -t tg-patch-changes.XXXXXX)"
-git diff --name-only $diff_opts "$base_rev" ${diff_committed_only:+"$name"} -- |
-	fgrep -vx ".topdeps" |
-	fgrep -vx ".topmsg" >"$git_is_stupid" || : # fgrep likes to fail randomly?
-if [ -s "$git_is_stupid" ]; then
-	cd "$root_dir"
-	cat "$git_is_stupid" | xargs git diff -a --patch-with-stat $diff_opts "$base_rev" ${diff_committed_only:+"$name"} --
-else
+
+# put out the commit message
+# and put an empty line out, if the last one in the message was not an empty line
+# and put out "---" if the commit message does not have one yet
+cat_file "$name:.topmsg" $head_from |
+	awk '
+/^---/ {
+    has_3dash=1;
+}
+       {
+    need_empty = 1;
+    if ($0 == "")
+        need_empty = 0;
+    print;
+}
+END    {
+    if (need_empty)
+        print "";
+    if (!has_3dash)
+        print "---";
+}
+'
+
+b_tree=$(pretty_tree "$name" -b)
+t_tree=$(pretty_tree "$name" $head_from)
+
+if [ $b_tree = $t_tree ]; then
 	echo "No changes."
+else
+	git diff-tree -p --stat $b_tree $t_tree
 fi
-rm "$git_is_stupid"
 
 echo '-- '
 echo "tg: ($base_rev..) $name (depends on: $(cat_file "$name:.topdeps" $head_from | paste -s -d' '))"
-- 
1.7.1.1067.g5aeb7