[TopGit PATCH v2] tg-patch: use pretty_tree

@@ -4,24 +4,18 @@
 # GPLv2
 
 name=
-
 topic=
-diff_opts=
-diff_committed_only=yes	# will be unset for index/worktree
-
+topic_for_pretty_tree=
 
 ## Parse options
 
 while [ -n "$1" ]; do
 	arg="$1"; shift
 	case "$arg" in
-	-i)
-		topic='(i)'
-		diff_opts="$diff_opts --cached";
-		diff_committed_only=;;
-	-w)
-		topic='(w)'
-		diff_committed_only=;;
+	-i|-w)
+		[ -z "$topic" ] || die "-i and -w are mutually exclusive"
+		topic="(${arg#-})"
+		topic_for_pretty_tree="$arg";;
 	-*)
 		echo "Usage: tg [...] patch [-i | -w] [NAME]" >&2
 		exit 1;;

@@ -32,8 +26,8 @@ while [ -n "$1" ]; do
 done
 
 
-[ -n "$name"  -a  -z "$diff_committed_only" ]  &&
-	die "-i/-w are mutually exclusive with NAME"
+[ -n "$name" -a -n "$topic" ] &&
+	die "$topic are mutually exclusive with NAME"
 
 [ -n "$name" ] || name="$(git symbolic-ref HEAD | sed 's#^refs/\(heads\|top-bases\)/##')"
 base_rev="$(git rev-parse --short --verify "refs/top-bases/$name" 2>/dev/null)" ||

@@ -46,22 +40,37 @@ base_rev="$(git rev-parse --short --verify "refs/top-bases/$name" 2>/dev/null)"
 
 setup_pager
 
-cat_file "$topic:.topmsg"
-echo
-[ -n "$(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
-	echo "No changes."
-fi
-rm "$git_is_stupid"
+# put out the commit message
+# and put an empty line out, if the last one in the message was not an empty line
+# and put out "---" if the commit message does not have one yet
+cat_file "$topic:.topmsg" |
+	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" $topic_for_pretty_tree)
+
+# use the ui diff command when the pager is active
+diff_command=diff
+[ "x$GIT_PAGER_IN_USE" = "x1" ] ||
+	diff_command=diff-tree
+
+git $diff_command -p --stat $b_tree $t_tree
 
 echo '-- '
 echo "tg: ($base_rev..) $name (depends on: $(cat_file "$topic:.topdeps" | paste -s -d' '))"