Merge branch 'PHP-7.3' into PHP-7.4

* PHP-7.3:
  Fix #76859 stream_get_line skips data if used with data-generating filter

Author: krakjoe

NEWS

@@ -10,6 +10,10 @@ PHP                                                                        NEWS
   . Fixed bug #75245 (Don't set content of elements with only whitespaces). 
     (eriklundin)
 
+- Standard:
+  . Fixed bug #76859 (stream_get_line skips data if used with data-generating 
+    filter). (kkopachev)
+
 03 Oct 2019, PHP 7.4.0RC3
 
 - Core:

ext/standard/tests/streams/bug46147.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Bug #46147 (after stream seek, appending stream filter reads incorrect data)
+--FILE--
+<?php
+$fp = tmpfile();
+fwrite($fp, "this is a lowercase string.\n");
+fseek($fp, 5);
+stream_filter_append($fp, "string.toupper");
+while (!feof($fp)) {
+    echo fread($fp, 5);
+}
+
+--EXPECT--
+IS A LOWERCASE STRING.

ext/standard/tests/streams/bug76859.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Bug #76859 (stream_get_line skips data if used with filters)
+--FILE--
+<?php
+
+$data = '123';
+
+$fh = fopen('php://memory', 'r+b');
+fwrite($fh, $data);
+rewind($fh);
+stream_filter_append($fh, 'string.rot13', STREAM_FILTER_READ);
+
+$out = '';
+while (!feof($fh)) {
+    $out .= stream_get_line($fh, 1024);
+}
+
+fclose($fh);
+
+echo strlen($out) . "\n";
+--EXPECT--
+3

main/streams/filter.c

@@ -360,8 +360,6 @@ PHPAPI int php_stream_filter_append_ex(php_stream_filter_chain *chain, php_strea
 			case PSFS_PASS_ON:
 				/* 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;
 

main/streams/streams.c

@@ -534,10 +534,6 @@ PHPAPI int _php_stream_fill_read_buffer(php_stream *stream, size_t size)
 		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);