Explicitly test against NULL; do not use !p or similar

Also added blanks lines after declarations in a couple of places.

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9916)

6 files changed, 13 insertions, 11 deletions

diff --git a/apps/crl.c b/apps/crl.c
index 49ad97b774..d36b93ba64 100644
--- a/apps/crl.c
+++ b/apps/crl.c
@@ -204,7 +204,7 @@ int crl_main(int argc, char **argv)
         }
         pkey = X509_get_pubkey(X509_OBJECT_get0_X509(xobj));
         X509_OBJECT_free(xobj);
-        if (!pkey) {
+        if (pkey == NULL) {
             BIO_printf(bio_err, "Error getting CRL issuer public key\n");
             goto end;
         }
@@ -228,7 +228,7 @@ int crl_main(int argc, char **argv)
         if (!newcrl)
             goto end;
         pkey = load_key(keyfile, keyformat, 0, NULL, NULL, "CRL signing key");
-        if (!pkey) {
+        if (pkey == NULL) {
             X509_CRL_free(newcrl);
             goto end;
         }
diff --git a/apps/genpkey.c b/apps/genpkey.c
index f8faf3ba94..afae4b656c 100644
--- a/apps/genpkey.c
+++ b/apps/genpkey.c
@@ -217,7 +217,7 @@ static int init_keygen_file(EVP_PKEY_CTX **pctx, const char *file, ENGINE *e)
     }
 
     pbio = BIO_new_file(file, "r");
-    if (!pbio) {
+    if (pbio == NULL) {
         BIO_printf(bio_err, "Can't open parameter file %s\n", file);
         return 0;
     }
@@ -225,7 +225,7 @@ static int init_keygen_file(EVP_PKEY_CTX **pctx, const char *file, ENGINE *e)
     pkey = PEM_read_bio_Parameters(pbio, NULL);
     BIO_free(pbio);
 
-    if (!pkey) {
+    if (pkey == NULL) {
         BIO_printf(bio_err, "Error reading parameter file %s\n", file);
         return 0;
     }
diff --git a/apps/lib/apps.c b/apps/lib/apps.c
index 5038817750..65bd5a4070 100644
--- a/apps/lib/apps.c
+++ b/apps/lib/apps.c
@@ -85,7 +85,7 @@ int chopup_args(ARGS *arg, char *buf)
         /* Skip whitespace. */
         while (*p && isspace(_UC(*p)))
             p++;
-        if (!*p)
+        if (*p == '\0')
             break;
 
         /* The start of something good :-) */
@@ -258,7 +258,7 @@ static char *app_get_pass(const char *arg, int keepbio)
 #endif
         } else if (strcmp(arg, "stdin") == 0) {
             pwdbio = dup_bio_in(FORMAT_TEXT);
-            if (!pwdbio) {
+            if (pwdbio == NULL) {
                 BIO_printf(bio_err, "Can't open BIO for stdin\n");
                 return NULL;
             }
@@ -407,7 +407,7 @@ static int load_pkcs12(BIO *in, const char *desc,
     if (PKCS12_verify_mac(p12, "", 0) || PKCS12_verify_mac(p12, NULL, 0)) {
         pass = "";
     } else {
-        if (!pem_cb)
+        if (pem_cb == NULL)
             pem_cb = (pem_password_cb *)password_callback;
         len = pem_cb(tpass, PEM_BUFSIZE, 0, cb_data);
         if (len < 0) {
diff --git a/apps/pkcs12.c b/apps/pkcs12.c
index 902b75029c..a708064db1 100644
--- a/apps/pkcs12.c
+++ b/apps/pkcs12.c
@@ -465,7 +465,7 @@ int pkcs12_main(int argc, char **argv)
         p12 = PKCS12_create(cpass, name, key, ucert, certs,
                             key_pbe, cert_pbe, iter, -1, keytype);
 
-        if (!p12) {
+        if (p12 == NULL) {
             ERR_print_errors(bio_err);
             goto export_end;
         }
diff --git a/apps/req.c b/apps/req.c
index 1c9672cca1..70b4f0d657 100644
--- a/apps/req.c
+++ b/apps/req.c
@@ -325,9 +325,10 @@ int req_main(int argc, char **argv)
             newreq = 1;
             break;
         case OPT_PKEYOPT:
-            if (!pkeyopts)
+            if (pkeyopts == NULL)
                 pkeyopts = sk_OPENSSL_STRING_new_null();
-            if (!pkeyopts || !sk_OPENSSL_STRING_push(pkeyopts, opt_arg()))
+            if (pkeyopts == NULL
+                    || !sk_OPENSSL_STRING_push(pkeyopts, opt_arg()))
                 goto opthelp;
             break;
         case OPT_SIGOPT:
diff --git a/apps/ts.c b/apps/ts.c
index 4ef8a72eef..aef74adce8 100644
--- a/apps/ts.c
+++ b/apps/ts.c
@@ -507,8 +507,9 @@ static int create_digest(BIO *input, const char *digest, const EVP_MD *md,
         md_value_len = EVP_MD_size(md);
     } else {
         long digest_len;
+
         *md_value = OPENSSL_hexstr2buf(digest, &digest_len);
-        if (!*md_value || md_value_len != digest_len) {
+        if (*md_value == NULL || md_value_len != digest_len) {
             OPENSSL_free(*md_value);
             *md_value = NULL;
             BIO_printf(bio_err, "bad digest, %d bytes "