d2i_X509.pod: clarify usage of the 'pp' function parameter

The 'pp' function parameters of d2i_TYPE() and i2d_TYPE() are referenced
in the DESCRIPTION section as 'in' resp. 'out'. This commit renames the
references to 'ppin' resp. 'ppout' and adds an explaining sentence.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5365)

diff --git a/doc/man3/d2i_X509.pod b/doc/man3/d2i_X509.pod
index 8096b39b1e981ce0bd407102faff66119497b376..80c5c9dd6d087be0b3809ec10f144b6ce3d25315 100644 (file)
--- a/doc/man3/d2i_X509.pod
+++ b/doc/man3/d2i_X509.pod
@@ -364,11 +364,11 @@ i2d_X509_VAL,
 
 =for comment generic
 
- TYPE *d2i_TYPE(TYPE **a, unsigned char **pp, long length);
+ TYPE *d2i_TYPE(TYPE **a, unsigned char **ppin, long length);
  TYPE *d2i_TYPE_bio(BIO *bp, TYPE **a);
  TYPE *d2i_TYPE_fp(FILE *fp, TYPE **a);
 
- int i2d_TYPE(TYPE *a, unsigned char **pp);
+ int i2d_TYPE(TYPE *a, unsigned char **ppout);
  int i2d_TYPE_fp(FILE *fp, TYPE *a);
  int i2d_TYPE_bio(BIO *bp, TYPE *a);
 
@@ -376,14 +376,16 @@ i2d_X509_VAL,
 
 In the description here, I<TYPE> is used a placeholder
 for any of the OpenSSL datatypes, such as I<X509_CRL>.
+The function parameters I<ppin> and I<ppout> are generally
+either both named I<pp> in the headers, or I<in> and I<out>.
 
 These functions convert OpenSSL objects to and from their ASN.1/DER
 encoding.  Unlike the C structures which can have pointers to sub-objects
 within, the DER is a serialized encoding, suitable for sending over the
 network, writing to a file, and so on.
 
-d2i_TYPE() attempts to decode B<len> bytes at B<*in>. If successful a
-pointer to the B<TYPE> structure is returned and B<*in> is incremented to
+d2i_TYPE() attempts to decode B<len> bytes at B<*ppin>. If successful a
+pointer to the B<TYPE> structure is returned and B<*ppin> is incremented to
 the byte following the parsed data.  If B<a> is not B<NULL> then a pointer
 to the returned structure is also written to B<*a>.  If an error occurred
 then B<NULL> is returned.
@@ -401,13 +403,13 @@ d2i_TYPE_fp() is similar to d2i_TYPE() except it attempts
 to parse data from FILE pointer B<fp>.
 
 i2d_TYPE() encodes the structure pointed to by B<a> into DER format.
-If B<out> is not B<NULL>, it writes the DER encoded data to the buffer
-at B<*out>, and increments it to point after the data just written.
+If B<ppout> is not B<NULL>, it writes the DER encoded data to the buffer
+at B<*ppout>, and increments it to point after the data just written.
 If the return value is negative an error occurred, otherwise it
 returns the length of the encoded data.
 
-If B<*out> is B<NULL> memory will be allocated for a buffer and the encoded
-data written to it. In this case B<*out> is not incremented and it points
+If B<*ppout> is B<NULL> memory will be allocated for a buffer and the encoded
+data written to it. In this case B<*ppout> is not incremented and it points
 to the start of the data just written.
 
 i2d_TYPE_bio() is similar to i2d_TYPE() except it writes
@@ -438,7 +440,7 @@ Therefore any FILE pointers or BIOs should be opened in binary mode.
 Functions such as strlen() will B<not> return the correct length
 of the encoded structure.
 
-The ways that B<*in> and B<*out> are incremented after the operation
+The ways that B<*ppin> and B<*ppout> are incremented after the operation
 can trap the unwary. See the B<WARNINGS> section for some common
 errors.
 The reason for this-auto increment behaviour is to reflect a typical