Rewrite PDO result binding

Instead of requiring the type to be determined in advance by the
describer function and then requiring get_col to return a buffer
of appropriate type, allow get_col to return an arbitrary zval.
See UPGRADING.INTERNALS for a more detailed description of the
change.

This makes the result fetching simpler, more efficient and more
flexible. The general possibility already existed via the special
PDO_PARAM_ZVAL type, but the usage was very inconvenient and/or
inefficient. Now it's possible to easily implement behavior like
"return int if it fits, otherwise string" and to avoid any kind
of complex management of temporary buffers.

This also fixes bug #40913 (our second highest voted bug of all
time, for some reason). PARAM_LOB result bindings will now
consistently return a stream resource, independently of the used
database driver.

I've tried my best to update all PDO drivers for this change, but
some of the changes may be broken, as I cannot test or even build
some of these drivers (in particular PDO dblib and PDO oci).
Fixes are appreciated -- a working CI setup would be even more
appreciated ;)

3 files changed, 37 insertions, 42 deletions

diff --git a/ext/pdo_mysql/mysql_statement.c b/ext/pdo_mysql/mysql_statement.c
index f2ba5aa95a..e1f6c6ff95 100644
--- a/ext/pdo_mysql/mysql_statement.c
+++ b/ext/pdo_mysql/mysql_statement.c
@@ -658,18 +658,13 @@ static int pdo_mysql_stmt_describe(pdo_stmt_t *stmt, int colno) /* {{{ */
 
 		cols[i].precision = S->fields[i].decimals;
 		cols[i].maxlen = S->fields[i].length;
-
-#ifdef PDO_USE_MYSQLND
-		cols[i].param_type = PDO_PARAM_ZVAL;
-#else
-		cols[i].param_type = PDO_PARAM_STR;
-#endif
 	}
 	PDO_DBG_RETURN(1);
 }
 /* }}} */
 
-static int pdo_mysql_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr, size_t *len, int *caller_frees) /* {{{ */
+static int pdo_mysql_stmt_get_col(
+		pdo_stmt_t *stmt, int colno, zval *result, enum pdo_param_type *type) /* {{{ */
 {
 	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
 
@@ -685,38 +680,33 @@ static int pdo_mysql_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr, size_
 	}
 #ifdef PDO_USE_MYSQLND
 	if (S->stmt) {
-		Z_TRY_ADDREF(S->stmt->data->result_bind[colno].zv);
-		*ptr = (char*)&S->stmt->data->result_bind[colno].zv;
+		ZVAL_COPY(result, &S->stmt->data->result_bind[colno].zv);
 	} else {
-		Z_TRY_ADDREF(S->current_row[colno]);
-		*ptr = (char*)&S->current_row[colno];
+		ZVAL_COPY(result, &S->current_row[colno]);
 	}
-	*len = sizeof(zval);
 	PDO_DBG_RETURN(1);
 #else
 	if (S->stmt) {
 		if (S->out_null[colno]) {
-			*ptr = NULL;
-			*len = 0;
 			PDO_DBG_RETURN(1);
 		}
-		*ptr = S->bound_result[colno].buffer;
-		if (S->out_length[colno] > S->bound_result[colno].buffer_length) {
+
+		size_t length = S->out_length[colno];
+		if (length > S->bound_result[colno].buffer_length) {
 			/* mysql lied about the column width */
 			strcpy(stmt->error_code, "01004"); /* truncated */
-			S->out_length[colno] = S->bound_result[colno].buffer_length;
-			*len = S->out_length[colno];
-			PDO_DBG_RETURN(0);
+			length = S->out_length[colno] = S->bound_result[colno].buffer_length;
 		}
-		*len = S->out_length[colno];
+		ZVAL_STRINGL_FAST(result, S->bound_result[colno].buffer, length);
 		PDO_DBG_RETURN(1);
 	}
 
 	if (S->current_data == NULL) {
 		PDO_DBG_RETURN(0);
 	}
-	*ptr = S->current_data[colno];
-	*len = S->current_lengths[colno];
+	if (S->current_data[colno]) {
+		ZVAL_STRINGL_FAST(result, S->current_data[colno], S->current_lengths[colno]);
+	}
 	PDO_DBG_RETURN(1);
 #endif
 } /* }}} */
@@ -815,7 +805,7 @@ static int pdo_mysql_stmt_col_meta(pdo_stmt_t *stmt, zend_long colno, zval *retu
 		add_assoc_string(return_value, "native_type", str);
 	}
 
-#ifdef PDO_USE_MYSQLND
+	enum pdo_param_type param_type;
 	switch (F->type) {
 		case MYSQL_TYPE_BIT:
 		case MYSQL_TYPE_YEAR:
@@ -826,13 +816,13 @@ static int pdo_mysql_stmt_col_meta(pdo_stmt_t *stmt, zend_long colno, zval *retu
 #if SIZEOF_ZEND_LONG==8
 		case MYSQL_TYPE_LONGLONG:
 #endif
-			add_assoc_long(return_value, "pdo_type", PDO_PARAM_INT);
+			param_type = PDO_PARAM_INT;
 			break;
 		default:
-			add_assoc_long(return_value, "pdo_type", PDO_PARAM_STR);
+			param_type = PDO_PARAM_STR;
 			break;
 	}
-#endif
+	add_assoc_long(return_value, "pdo_type", param_type);
 
 	add_assoc_zval(return_value, "flags", &flags);
 	add_assoc_string(return_value, "table", (char *) (F->table?F->table : ""));
diff --git a/ext/pdo_mysql/tests/pdo_mysql_stmt_blobs.phpt b/ext/pdo_mysql/tests/pdo_mysql_stmt_blobs.phpt
index 9bdd03d7bd..7f45e56b6b 100644
--- a/ext/pdo_mysql/tests/pdo_mysql_stmt_blobs.phpt
+++ b/ext/pdo_mysql/tests/pdo_mysql_stmt_blobs.phpt
@@ -48,9 +48,15 @@ MySQLPDOTest::skip();
             return false;
         }
 
-        if ($label !== $value) {
+        if (!is_resource($label)) {
+            printf("[%03d + 3] Returned value is not a stream resource\n", $offset);
+            return false;
+        }
+
+        $contents = stream_get_contents($label);
+        if ($contents !== $value) {
             printf("[%03d + 3] Returned value seems to be wrong (%d vs. %d characters). Check manually\n",
-                $offset, strlen($label), strlen($value));
+                $offset, strlen($contents), strlen($value));
             return false;
         }
 
diff --git a/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.phpt b/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.phpt
index b5b0275f04..0e87b118ee 100644
--- a/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.phpt
+++ b/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.phpt
@@ -139,23 +139,22 @@ try {
     $real_as_float = (false === stristr($row['_mode'], "REAL_AS_FLOAT")) ? false : true;
 
     $db->setAttribute(PDO::ATTR_STRINGIFY_FETCHES, false);
-    $is_mysqlnd = MySQLPDOTest::isPDOMySQLnd();
-    test_meta($db, 20, 'BIT(8)', 1, 'BIT', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 30, 'TINYINT', -127, 'TINY', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 40, 'TINYINT UNSIGNED', 255, 'TINY', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 50, 'BOOLEAN', 1, NULL, ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
+    test_meta($db, 20, 'BIT(8)', 1, 'BIT', PDO::PARAM_INT);
+    test_meta($db, 30, 'TINYINT', -127, 'TINY', PDO::PARAM_INT);
+    test_meta($db, 40, 'TINYINT UNSIGNED', 255, 'TINY', PDO::PARAM_INT);
+    test_meta($db, 50, 'BOOLEAN', 1, NULL, PDO::PARAM_INT);
 
-    test_meta($db, 60, 'SMALLINT', -32768, 'SHORT', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 70, 'SMALLINT UNSIGNED', 65535, 'SHORT', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
+    test_meta($db, 60, 'SMALLINT', -32768, 'SHORT', PDO::PARAM_INT);
+    test_meta($db, 70, 'SMALLINT UNSIGNED', 65535, 'SHORT', PDO::PARAM_INT);
 
-    test_meta($db, 80, 'MEDIUMINT', -8388608, 'INT24', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 90, 'MEDIUMINT UNSIGNED', 16777215, 'INT24', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
+    test_meta($db, 80, 'MEDIUMINT', -8388608, 'INT24', PDO::PARAM_INT);
+    test_meta($db, 90, 'MEDIUMINT UNSIGNED', 16777215, 'INT24', PDO::PARAM_INT);
 
-    test_meta($db, 100, 'INT', -2147483648, 'LONG', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
-    test_meta($db, 110, 'INT UNSIGNED', 4294967295, 'LONG', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
+    test_meta($db, 100, 'INT', -2147483648, 'LONG', PDO::PARAM_INT);
+    test_meta($db, 110, 'INT UNSIGNED', 4294967295, 'LONG', PDO::PARAM_INT);
 
-    test_meta($db, 120, 'BIGINT', '-9223372036854775808', 'LONGLONG', ($is_mysqlnd) ? ((PHP_INT_SIZE == 4) ? PDO::PARAM_STR : PDO::PARAM_INT) : PDO::PARAM_STR);
-    test_meta($db, 130, 'BIGINT UNSIGNED', '18446744073709551615', 'LONGLONG', ($is_mysqlnd) ? ((PHP_INT_SIZE == 4) ? PDO::PARAM_STR : PDO::PARAM_INT) : PDO::PARAM_STR);
+    test_meta($db, 120, 'BIGINT', '-9223372036854775808', 'LONGLONG', (PHP_INT_SIZE == 4) ? PDO::PARAM_STR : PDO::PARAM_INT);
+    test_meta($db, 130, 'BIGINT UNSIGNED', '18446744073709551615', 'LONGLONG', (PHP_INT_SIZE == 4) ? PDO::PARAM_STR : PDO::PARAM_INT);
 
     test_meta($db, 130, 'REAL', -1.01, ($real_as_float) ? 'FLOAT' : 'DOUBLE', PDO::PARAM_STR);
     test_meta($db, 140, 'REAL UNSIGNED', 1.01, ($real_as_float) ? 'FLOAT' : 'DOUBLE', PDO::PARAM_STR);
@@ -186,7 +185,7 @@ try {
     test_meta($db, 340, 'TIME', '14:37:00', 'TIME', PDO::PARAM_STR);
     test_meta($db, 350, 'TIMESTAMP', '2008-03-23 14:38:00', 'TIMESTAMP', PDO::PARAM_STR);
     test_meta($db, 360, 'DATETIME', '2008-03-23 14:38:00', 'DATETIME', PDO::PARAM_STR);
-    test_meta($db, 370, 'YEAR', '2008', 'YEAR', ($is_mysqlnd) ? PDO::PARAM_INT : PDO::PARAM_STR);
+    test_meta($db, 370, 'YEAR', '2008', 'YEAR', PDO::PARAM_INT);
 
     test_meta($db, 380, 'CHAR(1)', 'a', 'STRING', PDO::PARAM_STR);
     test_meta($db, 390, 'CHAR(10)', '0123456789', 'STRING', PDO::PARAM_STR);