Description:
------------
my app is supposed to scan directories for zip files, and put their contents into a database. since i am dealing with thousends of files there, it is likely that every now and then one of these archives is corrupted. it seems that under certain circumstances these archives will open and list their content fine, but extracting data from them fails.

this is what unzip has to say about one of these archives:

$ unzip -t ./test/arch/zip/c64demo.zip
Archive:  ./test/arch/zip/c64demo.zip
error [./test/arch/zip/c64demo.zip]:  missing 1 bytes in zipfile
  (attempting to process anyway)
error [./test/arch/zip/c64demo.zip]:  attempt to seek before beginning of zipfile
  (please check that you have transferred or created the zipfile in the
  appropriate BINARY mode and that you have compiled UnZip properly)
  (attempting to re-compensate)
    testing: 64DEMO.PAS               OK
    testing: MOB64.PAS                bad CRC 893e928b  (should be 3a92f29b)
file #3:  bad zipfile offset (local header sig):  3038
  (attempting to re-compensate)
    testing: NINJA3.PIC               OK
    testing: ZX-FLORD.PIC             OK
    testing: ROZNE.MOB                OK
    testing: SWISS.MBF                OK
    testing: TFIGHT.MOB               OK
    testing: LEONARDO.FNB             OK
    testing: NOTE-1.FNT               OK
    testing: MYLOGOV2.GFX             OK
At least one error was detected in ./test/arch/zip/c64demo.zip.

and zip says:

$ zip -T ./test/arch/zip/c64demo.zip
        zip warning: local header not found for NINJA3.PIC

with this archive, extracting the "MOB64.PAS" file will cause the extension to hang (no matter if i am using getStream/fread or getFromName).

the archive: http://hitmen.c02.at/temp/c64demo.zip

Reproduce code:
---------------
shortened excerpt from my code. i dont think this is relevant, it works fine with thousends of files.

	$za = new ZipArchive();
	$res =$za->open($zipname);
        if ($res === TRUE)		
	{
  	        $finfo=$za->statName($filename);
		$file_size=$finfo['size'];

		if($file_size>$MAX_PACKED_SCAN_FILELENGTH)
		{
			$contents=false;
		}
		else
		{
			 if($file_size>0)
			 {
// it hangs right here				$contents=$za->getFromName($filename);
				 
echo "<br>ZIP contents size:".strlen($contents);flush();ob_flush();	
					if(strlen($contents)!=$file_size)
					{	
						warning(modestr(1)." zip_readfile recorded data does not match unpacked size :".$zipname.":".$filename);
					}
			 }
	    		 else
			 {
			 	$contents=false;
			 	warning(modestr(1)." zip_readfile could not open stream from zero length file ".$zipname.":".$filename);
			 }
		}
		
		$za->close();
		return $contents;
	}
	else
	{
		warning(modestr(1)." zip_readfile could not read from ".$zipname.":".$filename);
		return false;
	}