Fix: PHP 8.1 pgsql change of return values (#43)

* Fix: PHP 8.1 pgsql change of return values

As per https://php.watch/versions/8.1/PgSQL-resource, PostgreSQL
extension has moved away from resource objects and is now
returning opaque classes (PgSQL\Connection, Result, Lob).

These classes no longer provide default conversions to (int), so
a different approach is required, while maintaining compatibility
to older PHP versions.

* Fixing a bug in tableInfo() method

My previous commit did not check for the right result structure
before raising an exception. While looking into this, I have found
a deprecation issue with Postgresql server versions >= 12 that
needed fixing as well (adsrc column was removed).

Context and recommended replacement: https://www.postgresql.org/docs/12/release-12.html#:~:text=obsolete%20pg_attrdef.-,adsrc,-column%20(Peter%20Eisentraut

* PR change as per comments received

* Errant space removed as per comment

* Added a catch-all statement to _resultId(...)

This completes the decision tree related to handling pg_() internal functions return types and function availability based on PHP versions. The statement is not normally expected to be executed with any current or historical PHP version, but having it seems like a good idea, at least for completeness.

* Semicolon added as per comment

Author: DanCld

DB/pgsql.php

@@ -143,6 +143,14 @@ class DB_pgsql extends DB_common
     var $_num_rows = array();
 
 
+    /**
+     * PostgreSQL server version, required for accomodating changes
+     * related to metadata column deprecations (i.e. pg_attrdef.adsrc)
+     * @var integer
+     * @access private
+     */
+    var $pg_major_server_version = 0;
+
     // }}}
     // {{{ constructor
 
@@ -186,12 +194,12 @@ function __construct()
      * Example of connecting to a new link via a socket:
      * <code>
      * require_once 'DB.php';
-     * 
+     *
      * $dsn = 'pgsql://user:pass@unix(/tmp)/dbname?new_link=true';
      * $options = array(
      *     'portability' => DB_PORTABILITY_ALL,
      * );
-     * 
+     *
      * $db = DB::connect($dsn, $options);
      * if (PEAR::isError($db)) {
      *     die($db->getMessage());
@@ -286,7 +294,13 @@ function connect($dsn, $persistent = false)
             return $this->raiseError(DB_ERROR_CONNECT_FAILED,
                                      null, null, null,
                                      $php_errormsg);
+	    }
+
+        if (function_exists('pg_version')) {
+            $pg_ver = pg_version($this->connection);
+            $this->pg_major_server_version = intval(array_key_exists('server', $pg_ver) ? $pg_ver['server'] : 0);
         }
+
         return DB_OK;
     }
 
@@ -355,12 +369,12 @@ function simpleQuery($query)
         } elseif (preg_match('/^\s*\(*\s*(SELECT|EXPLAIN|FETCH|SHOW|WITH)\s/si',
                              $query))
         {
-            $this->row[(int)$result] = 0; // reset the row counter.
+           $this->row[$this->_resultId($result)] = 0; // reset the row counter.
             $numrows = $this->numRows($result);
             if (is_object($numrows)) {
                 return $numrows;
             }
-            $this->_num_rows[(int)$result] = $numrows;
+            $this->_num_rows[$this->_resultId($result)] = $numrows;
             $this->affected = 0;
             return $result;
         } else {
@@ -399,7 +413,7 @@ function nextResult($result)
      * DB_result::fetchInto() instead.  It can't be declared "protected"
      * because DB_result is a separate object.
      *
-     * @param resource $result    the query result resource
+     * @param mixed    $result    the query result resource or PgSql\Result
      * @param array    $arr       the referenced array to put the data in
      * @param int      $fetchmode how the resulting array should be indexed
      * @param int      $rownum    the row number to fetch (0 = first row)
@@ -411,7 +425,7 @@ function nextResult($result)
      */
     function fetchInto($result, &$arr, $fetchmode, $rownum = null)
     {
-        $result_int = (int)$result;
+        $result_int = $this->_resultId($result);
         $rownum = ($rownum !== null) ? $rownum : $this->row[$result_int];
         if ($rownum >= $this->_num_rows[$result_int]) {
             return null;
@@ -447,17 +461,17 @@ function fetchInto($result, &$arr, $fetchmode, $rownum = null)
      * DB_result::free() instead.  It can't be declared "protected"
      * because DB_result is a separate object.
      *
-     * @param resource $result  PHP's query result resource
+     * @param mixed $result  PHP's query result resource or PgSql\Result
      *
      * @return bool  TRUE on success, FALSE if $result is invalid
      *
      * @see DB_result::free()
      */
     function freeResult($result)
     {
-        if (is_resource($result)) {
-            unset($this->row[(int)$result]);
-            unset($this->_num_rows[(int)$result]);
+        if (is_resource($result) || is_a($result, 'PgSql\Result')) {
+            unset($this->row[$this->_resultId($result)]);
+            unset($this->_num_rows[$this->_resultId($result)]);
             $this->affected = 0;
             return @pg_free_result($result);
         }
@@ -479,7 +493,7 @@ function freeResult($result)
     function quoteBoolean($boolean) {
         return $boolean ? 'TRUE' : 'FALSE';
     }
-     
+
     // }}}
     // {{{ escapeSimple()
 
@@ -525,7 +539,7 @@ function escapeSimple($str)
      * DB_result::numCols() instead.  It can't be declared "protected"
      * because DB_result is a separate object.
      *
-     * @param resource $result  PHP's query result resource
+     * @param mixed $result  PHP's query result resource or PgSql\Result
      *
      * @return int  the number of columns.  A DB_Error object on failure.
      *
@@ -550,7 +564,7 @@ function numCols($result)
      * DB_result::numRows() instead.  It can't be declared "protected"
      * because DB_result is a separate object.
      *
-     * @param resource $result  PHP's query result resource
+     * @param mixed $result  PHP's query result resource or PgSql\Result
      *
      * @return int  the number of rows.  A DB_Error object on failure.
      *
@@ -783,7 +797,7 @@ function pgsqlRaiseError($errno = null)
     /**
      * Gets the DBMS' native error message produced by the last query
      *
-     * {@internal Error messages are used instead of error codes 
+     * {@internal Error messages are used instead of error codes
      * in order to support older versions of PostgreSQL.}}
      *
      * @return string  the DBMS' error message
@@ -905,7 +919,7 @@ function tableInfo($result, $mode = null)
             $got_string = false;
         }
 
-        if (!is_resource($id)) {
+        if (!is_resource($id) && !is_a($id, 'PgSql\Result'))  {
             return $this->pgsqlRaiseError(DB_ERROR_NEED_MORE_DATA);
         }
 
@@ -957,16 +971,16 @@ function tableInfo($result, $mode = null)
      * and "multiple_key".  The default value is passed through
      * rawurlencode() in case there are spaces in it.
      *
-     * @param int $resource   the PostgreSQL result identifier
+     * @param int $id   the PostgreSQL result identifier
      * @param int $num_field  the field number
      *
      * @return string  the flags
      *
      * @access private
      */
-    function _pgFieldFlags($resource, $num_field, $table_name)
+    function _pgFieldFlags($id, $num_field, $table_name)
     {
-        $field_name = @pg_field_name($resource, $num_field);
+        $field_name = @pg_field_name($id, $num_field);
 
         // Check if there's a schema in $table_name and update things
         // accordingly.
@@ -990,7 +1004,10 @@ function _pgFieldFlags($resource, $num_field, $table_name)
             $flags  = ($row[0] == 't') ? 'not_null ' : '';
 
             if ($row[1] == 't') {
-                $result = @pg_query($this->connection, "SELECT a.adsrc
+                $select_field = $this->pg_major_server_version >= 12
+                    ? 'pg_get_expr(a.adbin, a.adrelid)'
+                    : 'a.adsrc';
+                $result = @pg_query($this->connection, "SELECT $select_field
                                     FROM $from, pg_attrdef a
                                     WHERE tab.relname = typ.typname AND typ.typrelid = f.attrelid
                                     AND f.attrelid = a.adrelid AND f.attname = '$field_name'
@@ -1110,6 +1127,33 @@ function _checkManip($query)
                 || parent::_checkManip($query));
     }
 
+    // }}}
+    // {{{ _resultId()
+
+    /**
+     * Returns a numeric value identifying the result, used for maintaining
+     * indexes. Required by migration from resources to 'PgSql\Result'
+     * types with PHP 8.1.
+     *
+     * @param mixed $result  the query result resource or PgSql\Result
+     *
+     * @return int
+     *
+     * @access protected
+     */
+    function _resultId($result)
+    {
+        return
+            is_resource($result)
+                ? ( function_exists('get_resource_id')
+                    ? get_resource_id($result)
+                    : (int)$result
+                ) : ( function_exists('spl_object_id')
+                    ? spl_object_id($result)
+                    // catch-all statement
+                    : (int)$result
+                );
+     }
 }
 
 /*