doc: document the new opt_legacy_okay() function's behaviour

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16022)

diff --git a/doc/internal/man3/OPTIONS.pod b/doc/internal/man3/OPTIONS.pod
index d615aa3c2881703442f9ac5a36a1678340c810f0..1971c76241bc2610a58954715a9ec62a0c5a4c1c 100644 (file)
--- a/doc/internal/man3/OPTIONS.pod
+++ b/doc/internal/man3/OPTIONS.pod
@@ -8,7 +8,7 @@ opt_begin, opt_next, opt_flag, opt_arg, opt_unknown, opt_cipher,
 opt_cipher_any, opt_cipher_silent, opt_md,
 opt_int, opt_int_arg, opt_long, opt_ulong, opt_intmax, opt_uintmax,
 opt_format, opt_isdir, opt_string, opt_pair,
-opt_num_rest, opt_rest
+opt_num_rest, opt_rest, opt_legacy_okay
 - Option parsing for commands and tests
 
 =head1 SYNOPSIS
@@ -53,6 +53,8 @@ opt_num_rest, opt_rest
  int opt_num_rest(void);
  char **opt_rest(void);
 
+ int opt_legacy_okay(void);
+
 =head1 DESCRIPTION
 
 The functions on this page provide a common set of option-parsing for
@@ -290,6 +292,12 @@ The opt_rest() function returns a pointer to the first non-option.
 If there were no parameters, it will point to the NULL that is
 at the end of the standard I<argv> array.
 
+The opt_legacy_okay() function returns true if no options have been
+specified that would preclude using legacy code paths.  Currently,
+the various provider options preclude legacy operation.  This means,
+for example, that specifying both B<-provider> and B<-engine> in the
+same command line will not work as expected.
+
 =head2 Common Options
 
 There are a few groups of options that are common to many OpenSSL programs.