*_free functions now accept NULL

Some *_free functions threw asserts when passed NULL. Now all of them
accept NULL as input and perform no action when called that way.

This gains us consistence for our free functions, and allows some
code simplifications where an explicit null check is no longer necessary.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 4c880f6b6f..4d17a8f216 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -400,7 +400,8 @@ crypto_new_pk_env(void)
 void
 crypto_free_pk_env(crypto_pk_env_t *env)
 {
-  tor_assert(env);
+  if (!env)
+    return;
 
   if (--env->refs > 0)
     return;
@@ -463,7 +464,8 @@ crypto_new_cipher_env(void)
 void
 crypto_free_cipher_env(crypto_cipher_env_t *env)
 {
-  tor_assert(env);
+  if (!env)
+    return;
 
   tor_assert(env->cipher);
   aes_free_cipher(env->cipher);
@@ -1528,6 +1530,8 @@ crypto_new_digest256_env(digest_algorithm_t algorithm)
 void
 crypto_free_digest_env(crypto_digest_env_t *digest)
 {
+  if (!digest)
+    return;
   memset(digest, 0, sizeof(crypto_digest_env_t));
   tor_free(digest);
 }
@@ -1899,7 +1903,8 @@ crypto_expand_key_material(const char *key_in, size_t key_in_len,
 void
 crypto_dh_free(crypto_dh_env_t *dh)
 {
-  tor_assert(dh);
+  if (!dh)
+    return;
   tor_assert(dh->dh);
   DH_free(dh->dh);
   tor_free(dh);