doc patch for pack("p",undef) packing a NULL pointer

I just noticed that the new feature where pack p/P will generate a NULL
pointer when given undef isn't documented anywhere. So here is a patch

p5p-msgid: 9708102159.AA11726@claudius.bfsec.bt.co.uk

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 0679822..8d191e8 100644 (file)
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -402,6 +402,9 @@ provides seven bits of the total value, with the most significant
 first.  Bit eight of each byte is set, except for the last byte, in
 which bit eight is clear.
 
+If 'p' or 'P' are given undef as values, they now generate a NULL
+pointer.
+
 Both pack() and unpack() now fail when their templates contain invalid
 types.  (Invalid types used to be ignored.)
 

diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod
index 4bf1fda..8f8424b 100644 (file)
--- a/pod/perlfunc.pod
+++ b/pod/perlfunc.pod
@@ -2160,7 +2160,9 @@ string that many nybbles long.  The "p" type packs a pointer to a null-
 terminated string.  You are responsible for ensuring the string is not a
 temporary value (which can potentially get deallocated before you get
 around to using the packed result).  The "P" packs a pointer to a structure
-of the size indicated by the length.  Real numbers (floats and doubles) are
+of the size indicated by the length. A NULL pointer is created if the 
+corresponding value for "p" or "P" is C<undef>.
+Real numbers (floats and doubles) are
 in the native machine format only; due to the multiplicity of floating
 formats around, and the lack of a standard "network" representation, no
 facility for interchange has been made.  This means that packed floating