427598 - msf file increases in size after viewing folder

Status: RESOLVED INVALID

(Thunderbird :: General, defect)

Description

[Duncan Cameron]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12
Build Identifier: 2.0.0.12 (20080213)

Simply by viewing a folder its msf file increases in size by a number of lines. In my simple tests it increased by 11 lines (below)

@$${6{@
<(91=1207594361)>[1:^9F(^AF^91)]
@$$}6}@

@$${7{@
<(92=Mon Apr 07 19:52:41 2008)>[1:^9F(^B6^92)]
@$$}7}@

@$${8{@
@$$}8}@

Similar lines are added each time that the folder is viewed, with just the timestamp varying, simply by clicking it in the folder list, even when there are no new emails or any emails deleted.
This seems to go on indefinitely, so the msf file will keep on increasing in size.
Compacting the folder seems to have no effect, but rebuilding the index does seem to remove the redundant lines.


Reproducible: Always

Steps to Reproduce:
1. create a new folder (e.g. test)
2. repeatedly open Thunderbird, select the folder from the folder pane and then close Thunderbird
3. view test.msf
Actual Results:  
test.msf has repeated instances of lines similar to those in the Details section.

Expected Results:  
test.msf should not increase in size

Comment 1

[WADA:World Anti-bad-Duping Agency]

To Duncan Cameron(bug opener):

Do you mean that ".msf" size increased infinitely by repeated "open & close" of mail folder in your test? (never be removed until Re-build Index?)

When I tested with Tb trunk 2008/4/07 build(local mail folder of a dummy POP3 account, MS Win-XP), one set of entries you pointed were written to ".msf" by one "open & close of folder", and several entries were added by several "open & close of folder". However, when "open & close of folder" were executed repeatedly, old sets of the data(looks to be open/close history for a period) were removed from ".msf", then file size of ".msf" was reduced.
i.e.
I couldn't observe infinite ".msf" file size increase by "local mail folder open/close".
 

Comment 2

[Duncan Cameron]

Yes you are right, the msf file does seem to be rebuilt at some point but I am not sure when.
When I originally saw the problem and experimented with opening/closing Thunderbird the file was not reduced, but I have seen it rebuilt today and reduced in size.

I would like to know at what point thunderbird decides to rebuilt the msf file, but will close this report as not being a bug.

Comment 3

[WADA:World Anti-bad-Duping Agency]

(In reply to comment #2)
> but I have seen it rebuilt today and reduced in size.

Size reduction by rebuild really? I felt in my test that sets of entries for access  history are removed on physical close, for example:
  1. folder open  => data is added to msf
  2. folder close(logical close) => data is added to msf (data is alive in cache)
  3. repeat 1/2
  4. cached data expires => physical close of msf => size is reduced