It doesn't make sense to try see if these variables are negative, since they're unsigned.

apps/speed.c

@@ -1044,7 +1044,7 @@ int MAIN(int argc, char **argv)
 			{
 			rsa_num=DSA_sign(EVP_PKEY_DSA,buf,20,buf2,
 				&kk,dsa_key[j]);
-			if (rsa_num <= 0)
+			if (rsa_num == 0)
 				{
 				BIO_printf(bio_err,"DSA sign failure\n");
 				ERR_print_errors(bio_err);
@@ -1067,7 +1067,7 @@ int MAIN(int argc, char **argv)
 			{
 			rsa_num2=DSA_verify(EVP_PKEY_DSA,buf,20,buf2,
 				kk,dsa_key[j]);
-			if (rsa_num2 <= 0)
+			if (rsa_num2 == 0)
 				{
 				BIO_printf(bio_err,"DSA verify failure\n");
 				ERR_print_errors(bio_err);

crypto/bio/bss_bio.c

@@ -250,7 +250,7 @@ static size_t bio_nread(BIO *bio, char **buf, size_t num)
 	available = bio_nread0(bio, buf);
 	if (num > available)
 		num = available;
-	if (num <= 0)
+	if (num == 0)
 		return num;
 
 	b = bio->ptr;
@@ -406,7 +406,7 @@ static size_t bio_nwrite(BIO *bio, char **buf, size_t num)
 	space = bio_nwrite0(bio, buf);
 	if (num > space)
 		num = space;
-	if (num <= 0)
+	if (num == 0)
 		return num;
 	b = bio->ptr;
 	assert(b != NULL);

ssl/s3_pkt.c

@@ -548,7 +548,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 		/* if it went, fall through and send more stuff */
 		}
 
-	if (len <= 0) return(len);
+	if (len == 0) return(len);
 	
 	wr= &(s->s3->wrec);
 	wb= &(s->s3->wbuf);
@@ -962,7 +962,7 @@ start:
 	memcpy(buf,&(rr->data[rr->off]),(unsigned int)n);
 	rr->length-=n;
 	rr->off+=n;
-	if (rr->length <= 0)
+	if (rr->length == 0)
 		{
 		s->rstate=SSL_ST_READ_HEADER;
 		rr->off=0;