Description:
------------
The following ./configure line breaks php 5.1.2 compilation:

niallm@socrates php-5.1.2 $ ./configure  --prefix=/usr/local/
php5/ --with-apxs-with-openssl --with-zlib --with-bz2 --with-
curl --enable-exif --enable-ftp --with-gd --with-mysql=//usr/
local/mysql-standard-4.1.12-apple-darwin7.9.0-powerpc/ --with-
pgsql=/usr/local/pgsql/ --enable-trans-sid --enable-sockets --
with-xmlrpc --with-pear --with-png-dir=/sw --with-jpeg-dir=/sw 
--with-tidy

Expected result:
----------------
I expect to see a compiled php binary ;-)

Actual result:
--------------
Instead compile fails in:

/bin/sh /Users/niallm/Downloads/php-5.1.2/libtool --silent 
--preserve-dup-deps --mode=compile gcc  -Iext/tidy/ -I/
Users/niallm/Downloads/php-5.1.2/ext/tidy/ -DPHP_ATOM_INC -
I/Users/niallm/Downloads/php-5.1.2/include -I/Users/niallm/
Downloads/php-5.1.2/main -I/Users/niallm/Downloads/php-5.1.2 
-I/usr/include/libxml2 -I/sw/include -I/Users/niallm/
Downloads/php-5.1.2/ext/date/lib -I//usr/local/mysql-
standard-4.1.12-apple-darwin7.9.0-powerpc//include -I/usr/
local/pgsql/include -I/usr/include/tidy -I/Users/niallm/
Downloads/php-5.1.2/TSRM -I/Users/niallm/Downloads/
php-5.1.2/Zend  -no-cpp-precomp  -I/usr/include -g -O2  -c /
Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c -o ext/
tidy/tidy.lo 
In file included from /usr/include/tidy/tidy.h:70,
                 from /Users/niallm/Downloads/php-5.1.2/ext/
tidy/tidy.c:37:
/usr/include/tidy/platform.h:515: error: duplicate 
'unsigned'
/usr/include/tidy/platform.h:515: warning: useless type name 
in empty declaration
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'php_tidy_quick_repair':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:493: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'tidy_doc_cast_handler':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:670: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'tidy_node_cast_handler':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:702: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'tidy_doc_update_properties':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:723: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:731: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'zif_ob_tidyhandler':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:1033: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'zif_tidy_get_error_buffer':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:1084: 
warning: pointer targets in initialization differ in 
signedness
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c: In 
function 'zif_tidy_get_output':
/Users/niallm/Downloads/php-5.1.2/ext/tidy/tidy.c:1100: 
warning: pointer targets in initialization differ in 
signedness
make: *** [ext/tidy/tidy.lo] Error 1