pretty: pass graph width to pretty formatting for use in '%>|(N)'

Pass graph width to pretty formatting, to make N in '%>|(N)'
include columns consumed by graph rendered when --graph option
is in use.

For example, in the output of

  git log --all --graph --pretty='format: [%>|(20)%h] %ar%d'

this change will make all commit hashes align at 20th column from
the edge of the terminal, not from the edge of the graph.

Signed-off-by: Josef Kufner <josef@kufner.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/commit.h b/commit.h
index b06db4d..0c923f0 100644
--- a/commit.h
+++ b/commit.h
@@ -161,6 +161,7 @@
 	 * should not be counted on by callers.
 	 */
 	struct string_list in_body_headers;
+	int graph_width;
 };
 
 struct userformat_want {
diff --git a/graph.c b/graph.c
index 1350bdd..ad766fa 100644
--- a/graph.c
+++ b/graph.c
@@ -669,6 +669,13 @@
 	graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
 }
 
+
+int graph_width(struct git_graph *graph)
+{
+	return graph->width;
+}
+
+
 static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
 {
 	/*
diff --git a/graph.h b/graph.h
index 0be62bd..3f48c19 100644
--- a/graph.h
+++ b/graph.h
@@ -68,6 +68,11 @@
 
 
 /*
+ * Return current width of the graph in on-screen characters.
+ */
+int graph_width(struct git_graph *graph);
+
+/*
  * graph_show_*: helper functions for printing to stdout
  */
 
diff --git a/log-tree.c b/log-tree.c
index 78a5381..8d39315 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -687,6 +687,8 @@
 	ctx.output_encoding = get_log_output_encoding();
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
+	if (opt->graph)
+		ctx.graph_width = graph_width(opt->graph);
 	pretty_print_commit(&ctx, commit, &msgbuf);
 
 	if (opt->add_signoff)
diff --git a/pretty.c b/pretty.c
index 87c4497..4f33b09 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1299,6 +1299,7 @@
 		if (!start)
 			start = sb->buf;
 		occupied = utf8_strnwidth(start, -1, 1);
+		occupied += c->pretty_ctx->graph_width;
 		padding = (-padding) - occupied;
 	}
 	while (1) {
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 7398605..d75cdbb 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -319,6 +319,19 @@
 	test_cmp expected actual
 '
 
+# Note: Space between 'message' and 'two' should be in the same column
+# as in previous test.
+test_expect_success 'right alignment formatting at the nth column with --graph. i18n.logOutputEncoding' '
+	git -c i18n.logOutputEncoding=$test_encoding log --graph --pretty="tformat:%h %>|(40)%s" >actual &&
+	iconv -f utf-8 -t $test_encoding >expected <<EOF&&
+* $head1                    message two
+* $head2                    message one
+* $head3                        add bar
+* $head4            $(commit_msg)
+EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'right alignment formatting with no padding' '
 	git log --pretty="tformat:%>(1)%s" >actual &&
 	cat <<EOF >expected &&
@@ -330,6 +343,17 @@
 	test_cmp expected actual
 '
 
+test_expect_success 'right alignment formatting with no padding and with --graph' '
+	git log --graph --pretty="tformat:%>(1)%s" >actual &&
+	cat <<EOF >expected &&
+* message two
+* message one
+* add bar
+* $(commit_msg)
+EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'right alignment formatting with no padding. i18n.logOutputEncoding' '
 	git -c i18n.logOutputEncoding=$test_encoding log --pretty="tformat:%>(1)%s" >actual &&
 	cat <<EOF | iconv -f utf-8 -t $test_encoding >expected &&