Bug 81284

Summary:	Opening a zero sized file modifies it on the disk with garbage
Product:	LibreOffice	Reporter:	Rpnpif <rpnpif>
Component:	LibreOffice	Assignee:	Maxim Monastirsky <momonasmon>
Status:	RESOLVED FIXED
Severity:	major	CC:	jbfaure, rpnpif
Priority:	medium
Version:	4.2.5.2 release
Hardware:	All
OS:	All
Whiteboard:	target:4.2.7
Crash report or crash signature:		Regression By:

Description Rpnpif 2014-07-13 08:27:50 UTC

To reproduce :

1. Create a zero sized file, as myfile.html or myfile.odt or other.
2. Open it in Libreoffice.
3. The file is displayed with garbage bytes. Without saving it, the file on the disk is modified !!
4. The Debian file command says after that : 
$ file myfile.html
Composite Document File V2 Document, No summary info.

Openoffice 4 has the same bug despite of an alert dialog box with a choice.

This bug should be considered as a security hole because it modifies unexpectedly a file. This file could have a role in the system as .gksu.lock or others.
All software must not modified involuntary an user file.

On Debian Wheezy 7.5.

Comment 1 Jean-Baptiste Faure 2014-07-13 19:57:52 UTC

Not reproducible for me with LibreOffice 4.3.1.0.0+ under Ubuntu 14.04 x86-64.
I created an empty file named new_test.odt. The file opened by LibreOffice is displayed empty and not changed when I close it without saving it (it is still O sized). Same behavior with a file named with html extension.

Best regards. JBF

Comment 2 Maxim Monastirsky 2014-07-14 08:20:02 UTC

Actually I fixed it for 4.3/master, but didn't backport to 4-2.

Comment 3 Commit Notification 2014-07-15 09:57:14 UTC

Maxim Monastirsky committed a patch related to this issue.
It has been pushed to "libreoffice-4-2":

http://cgit.freedesktop.org/libreoffice/core/commit/?id=70c5401aa3b063d0f275042a48a54f42c1f54c03&h=libreoffice-4-2

fdo#81284 Don't write to zero length files


It will be available in LibreOffice 4.2.7.

The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
http://wiki.documentfoundation.org/Testing_Daily_Builds
Affected users are encouraged to test the fix and report feedback.

Comment 4 Rpnpif 2014-07-21 10:16:32 UTC

(In reply to comment #3)

This patch seems to fix the bug for me (4.2.7 beta).

Thank you very much.