1 files changed, 75 insertions, 0 deletions
diff --git a/src/libgit2/message.c b/src/libgit2/message.c
new file mode 100644
index 000000000..ec0103a33
--- /dev/null
+++ b/src/libgit2/message.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "buf.h"
+
+#include "git2/message.h"
+
+static size_t line_length_without_trailing_spaces(const char *line, size_t len)
+{
+	while (len) {
+		unsigned char c = line[len - 1];
+		if (!git__isspace(c))
+			break;
+		len--;
+	}
+
+	return len;
+}
+
+/* Greatly inspired from git.git "stripspace" */
+/* see https://github.com/git/git/blob/497215d8811ac7b8955693ceaad0899ecd894ed2/builtin/stripspace.c#L4-67 */
+static int git_message__prettify(
+	git_str *message_out,
+	const char *message,
+	int strip_comments,
+	char comment_char)
+{
+	const size_t message_len = strlen(message);
+
+	int consecutive_empty_lines = 0;
+	size_t i, line_length, rtrimmed_line_length;
+	char *next_newline;
+
+	for (i = 0; i < strlen(message); i += line_length) {
+		next_newline = memchr(message + i, '\n', message_len - i);
+
+		if (next_newline != NULL) {
+			line_length = next_newline - (message + i) + 1;
+		} else {
+			line_length = message_len - i;
+		}
+
+		if (strip_comments && line_length && message[i] == comment_char)
+			continue;
+
+		rtrimmed_line_length = line_length_without_trailing_spaces(message + i, line_length);
+
+		if (!rtrimmed_line_length) {
+			consecutive_empty_lines++;
+			continue;
+		}
+
+		if (consecutive_empty_lines > 0 && message_out->size > 0)
+			git_str_putc(message_out, '\n');
+
+		consecutive_empty_lines = 0;
+		git_str_put(message_out, message + i, rtrimmed_line_length);
+		git_str_putc(message_out, '\n');
+	}
+
+	return git_str_oom(message_out) ? -1 : 0;
+}
+
+int git_message_prettify(
+	git_buf *message_out,
+	const char *message,
+	int strip_comments,
+	char comment_char)
+{
+	GIT_BUF_WRAP_PRIVATE(message_out, git_message__prettify, message, strip_comments, comment_char);
+}