1 files changed, 66 insertions, 0 deletions
diff --git a/strbuf.c b/strbuf.c
index 107c45d291..d76f0aed85 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -752,3 +752,69 @@ void strbuf_add_unique_abbrev(struct strbuf *sb, const unsigned char *sha1,
 	r = find_unique_abbrev_r(sb->buf + sb->len, sha1, abbrev_len);
 	strbuf_setlen(sb, sb->len + r);
 }
+
+/*
+ * Returns the length of a line, without trailing spaces.
+ *
+ * If the line ends with newline, it will be removed too.
+ */
+static size_t cleanup(char *line, size_t len)
+{
+	while (len) {
+		unsigned char c = line[len - 1];
+		if (!isspace(c))
+			break;
+		len--;
+	}
+
+	return len;
+}
+
+/*
+ * Remove empty lines from the beginning and end
+ * and also trailing spaces from every line.
+ *
+ * Turn multiple consecutive empty lines between paragraphs
+ * into just one empty line.
+ *
+ * If the input has only empty lines and spaces,
+ * no output will be produced.
+ *
+ * If last line does not have a newline at the end, one is added.
+ *
+ * Enable skip_comments to skip every line starting with comment
+ * character.
+ */
+void strbuf_stripspace(struct strbuf *sb, int skip_comments)
+{
+	int empties = 0;
+	size_t i, j, len, newlen;
+	char *eol;
+
+	/* We may have to add a newline. */
+	strbuf_grow(sb, 1);
+
+	for (i = j = 0; i < sb->len; i += len, j += newlen) {
+		eol = memchr(sb->buf + i, '\n', sb->len - i);
+		len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
+
+		if (skip_comments && len && sb->buf[i] == comment_line_char) {
+			newlen = 0;
+			continue;
+		}
+		newlen = cleanup(sb->buf + i, len);
+
+		/* Not just an empty line? */
+		if (newlen) {
+			if (empties > 0 && j > 0)
+				sb->buf[j++] = '\n';
+			empties = 0;
+			memmove(sb->buf + j, sb->buf + i, newlen);
+			sb->buf[newlen + j++] = '\n';
+		} else {
+			empties++;
+		}
+	}
+
+	strbuf_setlen(sb, j);
+}