Description:
------------
Building the pecl_http extension fails if optional CURL support is disabled.

Reproduce code:
---------------
Will upgrade pecl_http
[...]
Configuring for:
PHP Api Version:         20020918
Zend Module Api No:      20020429
Zend Extension Api No:   20021010
whether to enable cURL HTTP requests; specify libcurl directory [yes] : no
whether to enable support for gzencoded/deflated message bodies; specify zlib d irectory [yes] : no
whether to enable response content type guessing; specify libmagic directory [no] :
whether to depend on extensions which have been built shared [yes] :
[...]
checking whether to enable extended HTTP support... yes, shared
checking whether to enable cURL HTTP request support... no
checking whether to enable zlib encodings support... no
checking whether to enable response content type guessing... no
checking whether to depend on extensions which have been built shared... yes
[...]
/bin/sh /var/tmp/pear-build-root/pecl_http-1.3.2/libtool --mode=compile gcc  -I. -I/tmp/pear/cache/pecl_http-1.3.2 -DPHP_ATOM_INC -I/var/tmp/pear-build-root/pecl_http-1.3.2/include -I/var/tmp/pear-build-root/pecl_http-1.3.2/main -I/tmp/pear/cache/pecl_http-1.3.2 -I/usr/include/php4 -I/usr/include/php4/main -I/usr/include/php4/Zend -I/usr/include/php4/TSRM  -DHAVE_CONFIG_H  -g -O2   -c /tmp/pear/cache/pecl_http-1.3.2/http_request_info.c -o http_request_info.lo
 gcc -I. -I/tmp/pear/cache/pecl_http-1.3.2 -DPHP_ATOM_INC -I/var/tmp/pear-build-root/pecl_http-1.3.2/include -I/var/tmp/pear-build-root/pecl_http-1.3.2/main -I/tmp/pear/cache/pecl_http-1.3.2 -I/usr/include/php4 -I/usr/include/php4/main -I/usr/include/php4/Zend -I/usr/include/php4/TSRM -DHAVE_CONFIG_H -g -O2 -c /tmp/pear/cache/pecl_http-1.3.2/http_request_info.c  -fPIC -DPIC -o .libs/http_request_info.o

Expected result:
----------------
successful installation of pecl_http

Actual result:
--------------
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:21: error: syntax error before '*' token
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c: In function `_http_request_info':
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:28: error: `info' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:28: error: (Each undeclared identifier is reported only once
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:28: error: for each function it appears in.)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:31: error: `CURLE_OK' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:31: error: `request' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:31: error: `CURLINFO_EFFECTIVE_URL' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:34: error: `CURLINFO_RESPONSE_CODE' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:37: error: `CURLINFO_TOTAL_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:40: error: `CURLINFO_NAMELOOKUP_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:43: error: `CURLINFO_CONNECT_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:46: error: `CURLINFO_PRETRANSFER_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:49: error: `CURLINFO_SIZE_UPLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:52: error: `CURLINFO_SIZE_DOWNLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:55: error: `CURLINFO_SPEED_DOWNLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:58: error: `CURLINFO_SPEED_UPLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:61: error: `CURLINFO_HEADER_SIZE' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:64: error: `CURLINFO_REQUEST_SIZE' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:67: error: `CURLINFO_SSL_VERIFYRESULT' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:70: error: `CURLINFO_FILETIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:73: error: `CURLINFO_CONTENT_LENGTH_DOWNLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:76: error: `CURLINFO_CONTENT_LENGTH_UPLOAD' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:79: error: `CURLINFO_STARTTRANSFER_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:82: error: `CURLINFO_CONTENT_TYPE' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:85: error: `CURLINFO_REDIRECT_TIME' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:88: error: `CURLINFO_REDIRECT_COUNT' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:91: error: `CURLINFO_HTTP_CONNECTCODE' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:94: error: `CURLINFO_HTTPAUTH_AVAIL' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:97: error: `CURLINFO_PROXYAUTH_AVAIL' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:100: error: `CURLINFO_OS_ERRNO' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:103: error: `CURLINFO_NUM_CONNECTS' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:106: error: `CURLINFO_SSL_ENGINES' undeclared (first use in this function)
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:109: error: dereferencing pointer to incomplete type
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:110: error: dereferencing pointer to incomplete type
/tmp/pear/cache/pecl_http-1.3.2/http_request_info.c:115:22: missing binary operator before token "("
make: *** [http_request_info.lo] Error 1
ERROR: `make' failed