Add comments.

diff --git a/lib/getndelim2.c b/lib/getndelim2.c
index 1a0ec11..04349ad 100644 (file)
--- a/lib/getndelim2.c
+++ b/lib/getndelim2.c
@@ -105,7 +105,8 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
 
   while (!done)
     {
-      /* Here always ptr + size == read_pos + nbytes_avail.  */
+      /* Here always ptr + size == read_pos + nbytes_avail.
+        Also nbytes_avail > 0 || size < nmax.  */
 
       int c IF_LINT (= 0);
       const char *buffer;
@@ -171,6 +172,9 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
          read_pos = size - nbytes_avail + ptr;
        }
 
+      /* Here, if size < nmax, nbytes_avail >= buffer_len + 1.
+        If size == nmax, nbytes_avail > 0.  */
+
       if (1 < nbytes_avail)
        {
          size_t copy_len = nbytes_avail - 1;
@@ -183,6 +187,9 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
          read_pos += copy_len;
          nbytes_avail -= copy_len;
        }
+
+      /* Here still nbytes_avail > 0.  */
+
       if (buffer && freadseek (stream, buffer_len))
        goto unlock_done;
     }