Introduce git_buf_putcn

Allows for inserting the same character n amount of times

src/buffer.c

@@ -148,6 +148,15 @@ int git_buf_putc(git_buf *buf, char c)
 	return 0;
 }
 
+int git_buf_putcn(git_buf *buf, char c, size_t len)
+{
+	ENSURE_SIZE(buf, buf->size + len + 1);
+	memset(buf->ptr + buf->size, c, len);
+	buf->size += len;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
 int git_buf_put(git_buf *buf, const char *data, size_t len)
 {
 	ENSURE_SIZE(buf, buf->size + len + 1);

src/buffer.h

@@ -88,6 +88,7 @@ GIT_INLINE(bool) git_buf_oom(const git_buf *buf)
  */
 int git_buf_sets(git_buf *buf, const char *string);
 int git_buf_putc(git_buf *buf, char c);
+int git_buf_putcn(git_buf *buf, char c, size_t len);
 int git_buf_put(git_buf *buf, const char *data, size_t len);
 int git_buf_puts(git_buf *buf, const char *string);
 int git_buf_printf(git_buf *buf, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);