1 files changed, 15 insertions, 27 deletions

diff --git a/src/regress/lib/libcrypto/bio/bio_chain.c b/src/regress/lib/libcrypto/bio/bio_chain.c
index f5c46d710b..810395676f 100644
--- a/src/regress/lib/libcrypto/bio/bio_chain.c
+++ b/src/regress/lib/libcrypto/bio/bio_chain.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bio_chain.c,v 1.11 2022/12/09 17:23:05 tb Exp $       */
+/*      $OpenBSD: bio_chain.c,v 1.12 2022/12/10 10:42:13 tb Exp $       */
 /*
  * Copyright (c) 2022 Theo Buehler <tb@openbsd.org>
  *
@@ -200,24 +200,15 @@ walk_forward(BIO *start, BIO *end, size_t expected_len, size_t i, size_t j,
         size_t len;
         int ret = 0;
 
-        if (start == NULL || end == NULL) {
-                if (expected_len != 0) {
-                        fprintf(stderr, "%s case (%zu, %zu) %s: empty chain "
-                            "with expected length %zu > 0\n",
-                            fn, i, j, description, expected_len);
-                        goto err;
-                }
-                goto done;
-        }
-
+        prev = NULL;
         next = start;
         len = 0;
 
-        do {
+        while (next != NULL) {
                 prev = next;
                 next = BIO_next(prev);
                 len++;
-        } while (next != NULL);
+        }
 
         if (prev != end) {
                 fprintf(stderr, "%s case (%zu, %zu) %s has unexpected end\n",
@@ -232,7 +223,6 @@ walk_forward(BIO *start, BIO *end, size_t expected_len, size_t i, size_t j,
                 goto err;
         }
 
- done:
         ret = 1;
 
  err:
@@ -247,24 +237,15 @@ walk_backward(BIO *start, BIO *end, size_t expected_len, size_t i, size_t j,
         size_t len;
         int ret = 0;
 
-        if (start == NULL || end == NULL) {
-                if (expected_len != 0) {
-                        fprintf(stderr, "%s case (%zu, %zu) %s: empty chain "
-                            "with expected length %zu > 0\n",
-                            fn, i, j, description, expected_len);
-                        goto err;
-                }
-                goto done;
-        }
-
+        next = NULL;
         prev = end;
         len = 0;
 
-        do {
+        while (prev != NULL) {
                 next = prev;
                 prev = BIO_prev(prev);
                 len++;
-        } while (prev != NULL);
+        }
 
         if (next != start) {
                 fprintf(stderr, "%s case (%zu, %zu) %s has unexpected start\n",
@@ -279,7 +260,6 @@ walk_backward(BIO *start, BIO *end, size_t expected_len, size_t i, size_t j,
                 goto err;
         }
 
- done:
         ret = 1;
 
  err:
@@ -369,6 +349,7 @@ link_chains_at(size_t i, size_t j, int use_bio_push)
 
         new_start = A[0];
         new_end = B[nitems(B) - 1];
+        /* new_len depends on use_bio_push. It is set a few lines down. */
 
         oldhead_start = B[0];
         oldhead_end = BIO_prev(B[j]);
@@ -394,6 +375,13 @@ link_chains_at(size_t i, size_t j, int use_bio_push)
                 oldtail_start = BIO_next(A[i]);
                 oldtail_end = A[nitems(A) - 1];
                 oldtail_len = nitems(A) - i - 1;
+
+                /* If we set next on end of A[], the oldtail chain is empty. */
+                if (i == nitems(A) - 1) {
+                        oldtail_start = NULL;
+                        oldtail_end = NULL;
+                        oldtail_len = 0;
+                }
         }
 
         /* The two chains A[] and B[] are split into three disjoint pieces. */