Constify OSSL_HTTP_REQ_CTX_get0_mem_bio()

Reviewed-by: NPaul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13960)

crypto/http/http_client.c

@@ -116,7 +116,7 @@ void OSSL_HTTP_REQ_CTX_free(OSSL_HTTP_REQ_CTX *rctx)
     OPENSSL_free(rctx);
 }
 
-BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(OSSL_HTTP_REQ_CTX *rctx)
+BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(const OSSL_HTTP_REQ_CTX *rctx)
 {
     if (rctx == NULL) {
         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);

doc/man3/OSSL_HTTP_REQ_CTX.pod

@@ -40,7 +40,7 @@ OSSL_HTTP_REQ_CTX_set_max_response_length
  ASN1_VALUE *OSSL_HTTP_REQ_CTX_sendreq_d2i(OSSL_HTTP_REQ_CTX *rctx,
                                            const ASN1_ITEM *it);
 
- BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(OSSL_HTTP_REQ_CTX *rctx);
+ BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(const OSSL_HTTP_REQ_CTX *rctx);
  void OSSL_HTTP_REQ_CTX_set_max_response_length(OSSL_HTTP_REQ_CTX *rctx,
                                                 unsigned long len);
 

include/openssl/http.h

@@ -55,7 +55,7 @@ int OSSL_HTTP_REQ_CTX_i2d(OSSL_HTTP_REQ_CTX *rctx, const char *content_type,
 int OSSL_HTTP_REQ_CTX_nbio(OSSL_HTTP_REQ_CTX *rctx);
 ASN1_VALUE *OSSL_HTTP_REQ_CTX_sendreq_d2i(OSSL_HTTP_REQ_CTX *rctx,
                                           const ASN1_ITEM *it);
-BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(OSSL_HTTP_REQ_CTX *rctx);
+BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(const OSSL_HTTP_REQ_CTX *rctx);
 void OSSL_HTTP_REQ_CTX_set_max_response_length(OSSL_HTTP_REQ_CTX *rctx,
                                                unsigned long len);