From: Greg Beaver <cellog@php.net>
Date: Mon, 22 Sep 2008 01:26:38 +0000 (+0000)
Subject: MF52 fix Bug #46147: after stream seek, appending stream filter reads incorrect data
X-Git-Tag: BEFORE_HEAD_NS_CHANGE~346
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ae229cb86077060784036cb5ee875cc643bb81af;p=php

MF52 fix Bug #46147: after stream seek, appending stream filter reads incorrect data
---

diff --git a/main/streams/filter.c b/main/streams/filter.c
index 03e9974f7c..960df4c678 100644
--- a/main/streams/filter.c
+++ b/main/streams/filter.c
@@ -461,15 +461,12 @@ PHPAPI void _php_stream_filter_append(php_stream_filter_chain *chain, php_stream
 				stream->readpos = 0;
 				stream->writepos = 0;
 			} else if (status == PSFS_PASS_ON) {
-				/* Put any filtered data onto the readbuffer stack.
-				   Previously read data has been at least partially consumed. */
-				stream->readpos += consumed;
-
-				if (stream->writepos == stream->readpos) {
-					/* Entirely consumed */
-					stream->writepos = 0;
-					stream->readpos = 0;
-				}
+				/* If any data is consumed, we cannot rely upon the existing read buffer,
+				   as the filtered data must replace the existing data, so invalidate the cache */
+				/* note that changes here should be reflected in
+				   main/streams/streams.c::php_stream_fill_read_buffer */
+				stream->writepos = 0;
+				stream->readpos = 0;
 
 				while (brig_outp->head) {
 					bucket = brig_outp->head;
diff --git a/main/streams/streams.c b/main/streams/streams.c
index 8ca087727a..a2cbe888bb 100755
--- a/main/streams/streams.c
+++ b/main/streams/streams.c
@@ -455,6 +455,10 @@ static void php_stream_fill_read_buffer(php_stream *stream, size_t size TSRMLS_D
 		php_stream_bucket_brigade brig_in = { NULL, NULL }, brig_out = { NULL, NULL };
 		php_stream_bucket_brigade *brig_inp = &brig_in, *brig_outp = &brig_out, *brig_swap;
 
+		/* Invalidate the existing cache, otherwise reads can fail, see note in
+		   main/streams/filter.c::_php_stream_filter_append */
+		stream->writepos = stream->readpos = 0;
+
 		/* allocate a buffer for reading chunks */
 		chunk_buf = emalloc(stream->chunk_size);