Portability fixes for SCO and HPUX

Change TRUNCATE(number) to truncate towards zero for negative numbers
Fix NULL handling for DESCRIBE table_name


Docs/manual.texi:
  Update of TRUNCATE() information
configure.in:
  Fix for HPUX
extra/resolveip.c:
  Fix for SCO
include/my_net.h:
  Fix for HPUX
libmysql/libmysql.c:
  Removed warning on HPUX 10.20
mysql-test/r/func_math.result:
  Test of new TRUNCATE handling
mysql-test/t/func_math.test:
  Test of new TRUNCATE handling
mysys/my_gethostbyname.c:
  Portability fix
sql/item_func.cc:
  Change TRUNCATE(number) to truncate towards zero for negative numbers
sql/sql_show.cc:
  Fix NULL handling for DESCRIBE table_name

1 files changed, 16 insertions, 0 deletions

diff --git a/Docs/manual.texi b/Docs/manual.texi
index 431b6911393..d8b63c71726 100644
--- a/Docs/manual.texi
+++ b/Docs/manual.texi
@@ -31150,6 +31150,17 @@ mysql> select TRUNCATE(1.999,1);
         -> 1.9
 mysql> select TRUNCATE(1.999,0);
         -> 1
+mysql> select TRUNCATE(-1,999,1);
+        -> -1.9
+@end example
+
+Starting from MySQL 3.23.51 all numbers are rounded towards zero.
+
+If @code{D} is negative, then the whole part of the number is zeroed out:
+
+@example
+mysql> select truncate(122,-2);
+       -> 100
 @end example
 
 Note that as decimal numbers are normally not stored as exact numbers in
@@ -46916,6 +46927,11 @@ not yet 100% confident in this code.
 @appendixsubsec Changes in release 3.23.51
 @itemize @bullet
 @item
+Cleaned up @code{NULL} handling for default values in @code{DESCRIBE
+table_name}.
+@item
+Fixed @code{truncate()} to round up negative values to the nearest integer.
+@item
 Remove end space from @code{enum} values. (This fixed a problem with
 @code{SHOW CREATE TABLE}).
 @item