- Make fclose() actually close stream, even when the resource refcount is > 1.

cataphract · cataphract · commit 7f2937223dec · 2011-03-21T02:58:54.000Z
This reverts the fix for bug #24557. - Make php_stream_free delete the stream from the resources list, not merely decrease its refcount, as a single call to zend_list_delete does. #Not worth the risk merging to 5.3. While change php#2 may prevent some segfaults, #a quick and dirty survey to the codebase only showed calls to php_stream_close #or php_stream_free on streams allocated in the same function, which would have #refcount == 1. May be reconsidered.
diff --git a/UPGRADING b/UPGRADING
@@ -167,6 +167,8 @@ UPGRADE NOTES - PHP X.Y
 - stream_set_write_buffer() no longer disables the read buffer of a plain
   stream when 0 is given as the second argument.
 - stream_set_write_buffer() no longer changes the chunk size in socket streams.
+- fclose() closes streams with resource refcount > 1; it doesn't merely
+  decrement the resource refcount.
 
 ===================================
 5. Changes made to existing methods
diff --git a/ext/standard/file.c b/ext/standard/file.c
@@ -920,7 +920,7 @@ PHPAPI PHP_FUNCTION(fclose)
 	}
 
 	if (!stream->is_persistent) {
-		zend_list_delete(stream->rsrc_id);
+		php_stream_close(stream);
 	} else {
 		php_stream_pclose(stream);
 	}
diff --git a/ext/standard/tests/file/fclose_variation1.phpt b/ext/standard/tests/file/fclose_variation1.phpt
@@ -0,0 +1,15 @@
+--TEST--
+fclose() actually closes streams with refcount > 1
+--FILE--
+<?php
+$s = fopen(__FILE__, "rb");
+function separate_zval(&$var) { }
+$s2 = $s;
+separate_zval($s2);
+fclose($s);
+echo fread($s2, strlen("<?php"));
+echo "\nDone.\n";
+--EXPECTF--
+Warning: fread(): %d is not a valid stream resource in %s on line %d
+
+Done.
diff --git a/main/streams/streams.c b/main/streams/streams.c
@@ -331,7 +331,6 @@ static int _php_stream_free_persistent(zend_rsrc_list_entry *le, void *pStream T
 PHPAPI int _php_stream_free(php_stream *stream, int close_options TSRMLS_DC) /* {{{ */
 {
 	int ret = 1;
-	int remove_rsrc = 1;
 	int preserve_handle = close_options & PHP_STREAM_FREE_PRESERVE_HANDLE ? 1 : 0;
 	int release_cast = 1;
 	php_stream_context *context = stream->context;
@@ -395,15 +394,21 @@ PHPAPI int _php_stream_free(php_stream *stream, int close_options TSRMLS_DC) /*
 
 #if STREAM_DEBUG
 fprintf(stderr, "stream_free: %s:%p[%s] preserve_handle=%d release_cast=%d remove_rsrc=%d\n",
-		stream->ops->label, stream, stream->orig_path, preserve_handle, release_cast, remove_rsrc);
+		stream->ops->label, stream, stream->orig_path, preserve_handle, release_cast,
+		(close_options & PHP_STREAM_FREE_RSRC_DTOR) == 0);
 #endif
 
 	/* make sure everything is saved */
 	_php_stream_flush(stream, 1 TSRMLS_CC);
 
 	/* If not called from the resource dtor, remove the stream from the resource list. */
-	if ((close_options & PHP_STREAM_FREE_RSRC_DTOR) == 0 && remove_rsrc) {
-		zend_list_delete(stream->rsrc_id);
+	if ((close_options & PHP_STREAM_FREE_RSRC_DTOR) == 0) {
+		/* zend_list_delete actually only decreases the refcount; if we're
+		 * releasing the stream, we want to actually delete the resource from
+		 * the resource list, otherwise the resource will point to invalid memory.
+		 * In any case, let's always completely delete it from the resource list,
+		 * not only when PHP_STREAM_FREE_RELEASE_STREAM is set */
+		while (zend_list_delete(stream->rsrc_id) == SUCCESS) {}
 	}
 
 	/* Remove stream from any context link list */

Original file line number	Diff line number	Diff line change
`@@ -920,7 +920,7 @@ PHPAPI PHP_FUNCTION(fclose)`
`920`	`920`	`}`
`921`	`921`
`922`	`922`	`if (!stream->is_persistent) {`
`923`		`- zend_list_delete(stream->rsrc_id);`
	`923`	`+ php_stream_close(stream);`
`924`	`924`	`} else {`
`925`	`925`	`php_stream_pclose(stream);`
`926`	`926`	`}`