- * The contents of the `packed-refs` file. If the file was
- * already sorted, this points at the mmapped contents of the
- * file. If not, this points at heap-allocated memory
- * containing the contents, sorted. If there were no contents
- * (e.g., because the file didn't exist), `buf` and `eof` are
- * both NULL.
+ * The contents of the `packed-refs` file:
+ *
+ * - buf -- a pointer to the start of the memory
+ * - start -- a pointer to the first byte of actual references
+ * (i.e., after the header line, if one is present)
+ * - eof -- a pointer just past the end of the reference
+ * contents
+ *
+ * If the `packed-refs` file was already sorted, `buf` points
+ * at the mmapped contents of the file. If not, it points at
+ * heap-allocated memory containing the contents, sorted. If
+ * there were no contents (e.g., because the file didn't
+ * exist), `buf`, `start`, and `eof` are all NULL.