Description:
------------
Compiling PHP 5.1.2 on HP-UX 11.11 with pgsql 8.1.1 and OpenSSL support.

I don't have pkg-config on my system. configure gets it right at the beginning : checking for pkg-config... no

Then, in the pdo-pgsql section, I get :
  checking for openssl dependencies... yes
  ./configure[75167]: pkg-config:  not found.

I think that this code in ext/pdo_pgsql/config.m4 should be modified :

  AC_MSG_CHECKING([for openssl dependencies])
  if grep -q openssl $PGSQL_INCLUDE/libpq-fe.h ; then
         AC_MSG_RESULT([yes])
         if pkg-config openssl ; then
      PDO_PGSQL_CFLAGS="`pkg-config openssl --cflags`"
    fi
  else
         AC_MSG_RESULT([no])
  fi

There should be an alternate check for systems without pkg-config. Or pkg-config should be listed as a pre-requisite, which is not the case, is it ?

I cannot tell you more on a possible solution as I don't know exactly what pkg-config is supposed to say in this case.

In my case, after building and installing PHP, it seems to work OK. I didn't try pdo_pgsql more than loading it and checking in phpinfo that it is seen as enabled, but I didn't have any other error message during compile.

Reproduce code:
---------------
configure ... --with-pdo-pgsql=shared,<DIR>


Expected result:
----------------
Correct SSL dependencies even if pkg-config is not installed.

Actual result:
--------------
  checking for openssl dependencies... yes
  ./configure[75167]: pkg-config:  not found.