make ENGINE_finish() succeed on NULL and simplify callers as in

OpenSSL commit 7c96dbcdab9 by Rich Salz.

This cleans up the caller side quite a bit and reduces the number of
lines enclosed in #ifndef OPENSSL_NO_ENGINE.  codesearch.debian.net
shows that almost nothing checks the return value of ENGINE_finish().
While there, replace a few nearby 'if (!ptr)' with 'if (ptr == NULL)'.

ok jsing, tested by & ok inoguchi

1 files changed, 7 insertions, 13 deletions

diff --git a/src/lib/libcrypto/evp/p_lib.c b/src/lib/libcrypto/evp/p_lib.c
index 811fe0c86d..b14c95f14d 100644
--- a/src/lib/libcrypto/evp/p_lib.c
+++ b/src/lib/libcrypto/evp/p_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: p_lib.c,v 1.20 2018/02/20 18:05:28 tb Exp $ */
+/* $OpenBSD: p_lib.c,v 1.21 2018/04/14 07:09:21 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -229,11 +229,8 @@ pkey_set_type(EVP_PKEY *pkey, int type, const char *str, int len)
                 if ((type == pkey->save_type) && pkey->ameth)
                         return 1;
 #ifndef OPENSSL_NO_ENGINE
-                /* If we have an ENGINE release it */
-                if (pkey->engine) {
-                        ENGINE_finish(pkey->engine);
-                        pkey->engine = NULL;
-                }
+                ENGINE_finish(pkey->engine);
+                pkey->engine = NULL;
 #endif
         }
         if (str)
@@ -241,7 +238,7 @@ pkey_set_type(EVP_PKEY *pkey, int type, const char *str, int len)
         else
                 ameth = EVP_PKEY_asn1_find(&e, type);
 #ifndef OPENSSL_NO_ENGINE
-        if (!pkey && e)
+        if (pkey == NULL)
                 ENGINE_finish(e);
 #endif
         if (!ameth) {
@@ -426,8 +423,7 @@ EVP_PKEY_type(int type)
         else
                 ret = NID_undef;
 #ifndef OPENSSL_NO_ENGINE
-        if (e)
-                ENGINE_finish(e);
+        ENGINE_finish(e);
 #endif
         return ret;
 }
@@ -470,10 +466,8 @@ EVP_PKEY_free_it(EVP_PKEY *x)
                 x->pkey.ptr = NULL;
         }
 #ifndef OPENSSL_NO_ENGINE
-        if (x->engine) {
-                ENGINE_finish(x->engine);
-                x->engine = NULL;
-        }
+        ENGINE_finish(x->engine);
+        x->engine = NULL;
 #endif
 }