ext/pgsql: Add check for constant PGRES_TUPLES_CHUNK to fix compilation failures

close GH-17540

NEWS

@@ -65,6 +65,10 @@ PHP                                                                        NEWS
     the cpu mask argument with entries type different than int/string.
     (David Carlier)
 
+- PgSql:
+  . Fixed build failure when the constant PGRES_TUPLES_CHUNK is not present
+    in the system. (chschneider)
+
 - Phar:
   . Fixed bug GH-17518 (offset overflow phar extractTo()). (nielsdos)
 

ext/pgsql/config.m4

@@ -28,15 +28,19 @@ if test "$PHP_PGSQL" != "no"; then
       [Define to 1 if libpq has the 'PQsocketPoll' function (PostgreSQL 17 or
       later).])],,
     [$PGSQL_LIBS])
-  PHP_CHECK_LIBRARY([pq], [PQsetChunkedRowsMode],
-    [AC_DEFINE([HAVE_PG_SET_CHUNKED_ROWS_SIZE], [1],
-      [Define to 1 if libpq has the 'PQsetChunkedRowsMode' function (PostgreSQL
-      17 or later).])],,
-    [$PGSQL_LIBS])
 
   old_CFLAGS=$CFLAGS
   CFLAGS="$CFLAGS $PGSQL_CFLAGS"
 
+  AC_CHECK_DECLS([PGRES_TUPLES_CHUNK],
+    PHP_CHECK_LIBRARY([pq], [PQsetChunkedRowsMode],
+      [AC_DEFINE([HAVE_PG_SET_CHUNKED_ROWS_SIZE], [1],
+        [Define to 1 if libpq has the 'PQsetChunkedRowsMode' function (PostgreSQL
+        17 or later).])],,
+      [$PGSQL_LIBS]),,
+      [#include <libpq-fe.h>]
+  )
+
   dnl Available since PostgreSQL 12.
   AC_CACHE_CHECK([if PGVerbosity enum has PQERRORS_SQLSTATE],
     [php_cv_enum_pgverbosity_pqerrors_sqlstate],