Bug #68948 [Com]: feof() on temporary streams broken
Edit report at https://bugs.php.net/bug.php?id=68948&edit=1
ID: 68948
Comment by: slusarz at horde dot org
Reported by: yunosh@php.net
Summary: feof() on temporary streams broken
Status: Open
Type: Bug
Package: Streams related
Operating System: Linux
PHP Version: 5.6.5
Block user comment: N
Private report: N
New Comment:
The previous way of handling EOFs in memory streams was entirely compatible with the fread()
documentation -- http://php.net/manual/en/function.fread.php
-- which clearly states (emphasis mine):
"When reading from **anything that is not a regular local file** ... reading will stop after a
packet is available. This means that you should collect the data together in chunks.... (Example
loops through fread() to build a string; it doesn't rely on feof() to return true immediately
when the end of string is reached.)"
In other words, this can be stated as: "When reading from a memory stream, which is NOT a
regular local file, it cannot be guaranteed that at the end of any fread() operation that EOF has
been reached."
Any code that requires feof() to return true in a in-memory stream immediately after a non-empty
fread() return is broken, since this is non-guaranteed behavior. Thus, this fix must be reverted as
it is a backward incompatible change. the base64 filter (or filter code in general) is the
problematic code and is what needs to be fixed.
Previous Comments:
------------------------------------------------------------------------
[2015-02-09 19:53:39] yunosh@php.net
Changing version because this is a major regression in the latest stable 5.5 and 5.6 releases too.
------------------------------------------------------------------------
[2015-02-07 13:08:53] sjaillet at gmail dot com
It's definitely a bug introduced recently.
Indeed with:
$stream = fopen("php://temp", "r+");
fwrite($stream, "0123456789");
rewind($stream);
var_dump(fread($stream, 1024), ftell($stream), feof($stream));
The output for 5.5.20, 5.6.4, php7@20141201, HHVM 3.5.0 is:
string(10) "0123456789"
int(10)
bool(true)
And now with 5.5.21, 5.6.5, php7@20150101 the output was:
string(10) "0123456789"
int(10)
bool(false)
------------------------------------------------------------------------
[2015-01-29 20:02:47] yunosh@php.net
It still happens if reading 11 bytes. And even with 10 bytes, this would be BC break against PHP 5.
------------------------------------------------------------------------
[2015-01-29 19:15:29] php at mcq8 dot be
This is due to https://github.com/php/php-src/pull/936
You only get an EOF when you tried to read more than there is data.
This is the same behaviour as reading from a file.
------------------------------------------------------------------------
[2015-01-29 17:42:00] yunosh@php.net
Description:
------------
feof() doesn't work properly on temporary streams.
Test script:
---------------
$stream = fopen("php://temp", "r+");
fwrite($stream, "0123456789");
rewind($stream);
var_dump(fread($stream, 10), ftell($stream), feof($stream));
Expected result:
----------------
string(10) "0123456789"
int(10)
bool(true)
Actual result:
--------------
string(10) "0123456789"
int(10)
bool(false)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=68948&edit=1
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