This looks like a good fix that should go into trunk, but who posted it? 
On squeaksource.com, 'jdr' is Javier Diaz Reinoso, but I cannot connect it
to a user on source.squeak.org ???

Dave


On Thu, Dec 31, 2015 at 11:14:01PM +0000, commits at source.squeak.org wrote:
> A new version of Compression was added to project The Inbox:
> http://source.squeak.org/inbox/Compression-jdr.48.mcz
> 
> ==================== Summary ====================
> 
> Name: Compression-jdr.48
> Author: jdr
> Time: 31 December 2015, 6:13:59.974 pm
> UUID: 7798d7c6-8f39-45cc-a3cc-e0887130a62d
> Ancestors: Compression-dtl.47
> 
> It solves a problem compressing a zipfile with many files (> 200), previously all files to be processed remained open, now only the file being processed is opened.
> 
> =============== Diff against Compression-dtl.47 ===============
> 
> Item was changed:
>   ----- Method: ZipArchive>>writeTo: (in category 'writing') -----
>   writeTo: stream
>   	stream binary.
>   	members do: [ :member |
>   		member writeTo: stream.
>   		member endRead.
> + 		member close
>   	].
>   	writeCentralDirectoryOffset := stream position.
>   	self writeCentralDirectoryTo: stream.
>   	!
> 
> Item was changed:
>   ----- Method: ZipArchive>>writeTo:prepending: (in category 'writing') -----
>   writeTo: stream prepending: aString
>   	stream binary.
>   	stream nextPutAll: aString.
>   	members do: [ :member |
>   		member writeTo: stream.
>   		member endRead.
> + 		member close
>   	].
>   	writeCentralDirectoryOffset := stream position.
>   	self writeCentralDirectoryTo: stream.
>   	!
> 
> Item was changed:
>   ----- Method: ZipNewFileMember>>from: (in category 'initialization') -----
>   from: aFileName
>   	| entry |
>   	compressionMethod := CompressionStored.
>   	"Now get the size, attributes, and timestamps, and see if the file exists"
>   	stream := StandardFileStream readOnlyFileNamed: aFileName.
>   	self localFileName: (externalFileName := stream name).
>   	entry := stream directoryEntry.
>   	compressedSize := uncompressedSize := entry fileSize.
>   	desiredCompressionMethod := compressedSize > 0 ifTrue: [ CompressionDeflated ] ifFalse: [ CompressionStored ].
> + 	self setLastModFileDateTimeFrom: entry modificationTime.
> + 	stream close
> - 	self setLastModFileDateTimeFrom: entry modificationTime
>   !
> 
> Item was changed:
>   ----- Method: ZipNewFileMember>>rewindData (in category 'private-writing') -----
>   rewindData
>   	super rewindData.
> + 	stream ensureOpen.
>   	readDataRemaining := stream size.
>   	stream position: 0.!
>