- Behavior when seeking past the end of file.

Partially addresses bug #52335.
- Expanded note on how the stream may not support seeking.

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@305317 c90b9560-bf6c-de11-be94-00142212c4b1

reference/filesystem/functions/fseek.xml

@@ -21,6 +21,13 @@
    <parameter>offset</parameter> to the position specified by
    <parameter>whence</parameter>.
   </para>
+  <para>
+   In general, it is allowed to seek past the end-of-file; if data is then
+   written, reads in any unwritten region between the end-of-file and the
+   sought position will yield bytes with value 0. However, certain streams
+   may not support this behavior, especially when they have an underlying
+   fixed size storage.
+  </para>
  </refsect1>
 
  <refsect1 role="parameters">
@@ -67,8 +74,7 @@
  <refsect1 role="returnvalues">
   &reftitle.returnvalues;
   <para>
-   Upon success, returns 0; otherwise, returns -1. Note that seeking
-   past EOF is not considered an error.
+   Upon success, returns 0; otherwise, returns -1.
   </para>
  </refsect1>
 
@@ -109,9 +115,9 @@ fseek($fp, 0);
   </note>
   <note>
    <para>
-    May not be used on file pointers returned by <function>fopen</function> if
-    they use the <literal>http://</literal> or <literal>ftp://</literal>
-    schemes.
+    Not all streams support seeking. For those that do not support seeking,
+    forward seeking from the current position is accomplished by reading
+    and discarding data; other forms of seeking will fail.
    </para>
   </note>
  </refsect1>